Snap sync interval range extractor (#1449)

* Update comments and test noise

* Fix boundary proofs

why:
  Where neither used in production, nor unit tested. For production, other
  methods apply to test leaf range integrity directly based of the proof
  nodes.

* Added `hexary_range()`: interval range + proof extractor

details:
+ Will be used for `snap/1` protocol handler
+ Unit tests added (also for testing left boundary proof)

todo:
  Need to verify completeness of proof nodes

* Reduce some nim 1.6 compiler noise

* Stop unit test gossip for ci tests

nimbus/sync/handlers/snap.nim

@@ -11,9 +11,9 @@
 import
   chronicles,
   chronos,
-  eth/[p2p, p2p/peer_pool],
+  eth/p2p,
   ../protocol,
-  ../protocol/[snap/snap_types, trace_config],
+  ../protocol/snap/snap_types,
   ../../core/chain
 
 {.push raises: [Defect].}

nimbus/sync/protocol/snap/snap_types.nim

@@ -10,7 +10,7 @@
 
 import
   chronicles,
-  eth/[common, p2p, p2p/private/p2p_types]
+  eth/[common, p2p/private/p2p_types]
 #  ../../types
 
 type

nimbus/sync/snap/worker.nim

@@ -9,7 +9,7 @@
 # except according to those terms.
 
 import
-  std/[hashes, options, sets, strutils],
+  std/[options, sets, strutils],
   chronicles,
   chronos,
   eth/[common, p2p],

nimbus/sync/snap/worker/db/hexary_desc.nim

@@ -407,6 +407,24 @@ proc convertTo*(node: RNodeRef; T: type Blob): T =
 
   writer.finish()
 
+proc convertTo*(node: XNodeObj; T: type Blob): T =
+  ## Variant of above `convertTo()` for `XNodeObj` nodes.
+  var writer = initRlpWriter()
+
+  case node.kind:
+  of Branch:
+    writer.append(node.bLink)
+  of Extension:
+    writer.startList(2)
+    writer.append(node.ePfx.hexPrefixEncode(isleaf = false))
+    writer.append(node.eLink)
+  of Leaf:
+    writer.startList(2)
+    writer.append(node.lPfx.hexPrefixEncode(isleaf = true))
+    writer.append(node.lData)
+
+  writer.finish()
+
 # ------------------------------------------------------------------------------
 # End
 # ------------------------------------------------------------------------------

nimbus/sync/snap/worker/db/hexary_envelope.nim

@@ -70,15 +70,6 @@
 ## * then there is a ``w = partialPath & w-ext`` in ``W`` with
 ##   ``p-ext = w-ext & some-ext``.
 ##
-## Relation to boundary proofs
-## ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-## Consider the decomposition of an empty *partial path* (the envelope of which
-## representing the whole leaf node path range) for a leaf node range `iv`.
-## This result is then a `boundary proof` for `iv` according to the definition
-## above though it is highly redundant. All *partial path* bottom level nodes
-## with envelopes disjunct to `iv` can be removed from `W` for a `boundary
-## proof`.
-##
 import
   std/[algorithm, sequtils, tables],
   eth/[common, trie/nibbles],
@@ -160,41 +151,41 @@ proc padPartialPath(pfx: NibblesSeq; dblNibble: byte): NodeKey =
 
 
 proc doDecomposeLeft(
-    envPt: RPath|XPath;
+    envQ: RPath|XPath;
-    ivPt: RPath|XPath;
+    ivQ: RPath|XPath;
       ): Result[seq[NodeSpecs],HexaryError] =
   ## Helper for `hexaryEnvelopeDecompose()` for handling left side of
   ## envelope from partial path argument
   #
-  #      partialPath
+  #              partialPath
-  #       /     \
+  #               /      \
-  #      /       \
+  #              /        \
-  #    envPt..              -- envelope left end of partial path
+  #   ivQ[x]==envQ[x]      \       -- envelope left end of partial path
-  #        |
+  #     |                   \
-  #      ivPt..             -- `iv`, not fully covering left of `env`
+  #   ivQ[x+1]                     -- `iv`, not fully covering left of `env`
+  #     :
   #
   var collect: seq[NodeSpecs]
   block rightCurbEnvelope:
-    for n in 0 ..< min(envPt.path.len+1, ivPt.path.len):
+    for n in 0 ..< min(envQ.path.len+1, ivQ.path.len):
-      if n == envPt.path.len or envPt.path[n] != ivPt.path[n]:
+      if n == envQ.path.len or envQ.path[n] != ivQ.path[n]:
         #
-        # At this point, the `node` entries of either `path[n]` step are
+        # At this point, the `node` entries of either `.path[n]` step are
         # the same. This is so because the predecessor steps were the same
         # or were the `rootKey` in case n == 0.
         #
-        # But then (`node` entries being equal) the only way for the
+        # But then (`node` entries being equal) the only way for the `.path[n]`
-        # `path[n]` steps to differ is in the entry selector `nibble` for
+        # steps to differ is in the entry selector `nibble` for a branch node.
-        # a branch node.
         #
-        for m in n ..< ivPt.path.len:
+        for m in n ..< ivQ.path.len:
           let
-            pfx = ivPt.getNibbles(0, m) # common path segment
+            pfx = ivQ.getNibbles(0, m) # common path segment
-            top = ivPt.path[m].nibble   # need nibbles smaller than top
+            top = ivQ.path[m].nibble   # need nibbles smaller than top
           #
           # Incidentally for a non-`Branch` node, the value `top` becomes
           # `-1` and the `for`- loop will be ignored (which is correct)
           for nibble in 0 ..< top:
-            let nodeKey = ivPt.path[m].node.bLink[nibble]
+            let nodeKey = ivQ.path[m].node.bLink[nibble]
             if not nodeKey.isZeroLink:
               collect.add nodeKey.toNodeSpecs hexPrefixEncode(
                 pfx & @[nibble.byte].initNibbleRange.slice(1),isLeaf=false)
@@ -210,30 +201,31 @@ proc doDecomposeLeft(
   ok(collect)
 
 proc doDecomposeRight(
-    envPt: RPath|XPath;
+    envQ: RPath|XPath;
-    ivPt: RPath|XPath;
+    ivQ: RPath|XPath;
       ): Result[seq[NodeSpecs],HexaryError] =
   ## Helper for `hexaryEnvelopeDecompose()` for handling right side of
   ## envelope from partial path argument
   #
-  #        partialPath
+  #      partialPath
-  #         /     \
+  #       /        \
-  #        /       \
+  #      /          \
-  #           .. envPt     -- envelope right end of partial path
+  #     /  ivQ[x]==envQ[^1]     -- envelope right end of partial path
-  #              |
+  #    /     |
-  #          .. ivPt       -- `iv`, not fully covering right of `env`
+  #        ivQ[x+1]             -- `iv`, not fully covering right of `env`
+  #          :
   #
   var collect: seq[NodeSpecs]
   block leftCurbEnvelope:
-    for n in 0 ..< min(envPt.path.len+1, ivPt.path.len):
+    for n in 0 ..< min(envQ.path.len+1, ivQ.path.len):
-      if n == envPt.path.len or envPt.path[n] != ivPt.path[n]:
+      if n == envQ.path.len or envQ.path[n] != ivQ.path[n]:
-        for m in n ..< ivPt.path.len:
+        for m in n ..< ivQ.path.len:
           let
-            pfx = ivPt.getNibbles(0, m) # common path segment
+            pfx = ivQ.getNibbles(0, m) # common path segment
-            base = ivPt.path[m].nibble  # need nibbles greater/equal
+            base = ivQ.path[m].nibble  # need nibbles greater/equal
           if 0 <= base:
             for nibble in base+1 .. 15:
-              let nodeKey = ivPt.path[m].node.bLink[nibble]
+              let nodeKey = ivQ.path[m].node.bLink[nibble]
               if not nodeKey.isZeroLink:
                 collect.add nodeKey.toNodeSpecs hexPrefixEncode(
                   pfx & @[nibble.byte].initNibbleRange.slice(1),isLeaf=false)
@@ -258,15 +250,15 @@ proc decomposeLeftImpl(
   # non-matching of the below if clause.
   if env.minPt < iv.minPt:
     let
-      envPt = env.minPt.hexaryPath(rootKey, db)
+      envQ = env.minPt.hexaryPath(rootKey, db)
       # Make sure that the min point is the nearest node to the right
-      ivPt = block:
+      ivQ = block:
         let rc = iv.minPt.hexaryPath(rootKey, db).hexaryNearbyRight(db)
         if rc.isErr:
           return err(rc.error)
         rc.value
     block:
-      let rc = envPt.doDecomposeLeft ivPt
+      let rc = envQ.doDecomposeLeft ivQ
       if rc.isErr:
         return err(rc.error)
       nodeSpex &= rc.value
@@ -285,14 +277,14 @@ proc decomposeRightImpl(
   var nodeSpex: seq[NodeSpecs]
   if iv.maxPt < env.maxPt:
     let
-      envPt = env.maxPt.hexaryPath(rootKey, db)
+      envQ = env.maxPt.hexaryPath(rootKey, db)
-      ivPt = block:
+      ivQ = block:
         let rc = iv.maxPt.hexaryPath(rootKey, db).hexaryNearbyLeft(db)
         if rc.isErr:
           return err(rc.error)
         rc.value
     block:
-      let rc = envPt.doDecomposeRight ivPt
+      let rc = envQ.doDecomposeRight ivQ
       if rc.isErr:
         return err(rc.error)
       nodeSpex &= rc.value

nimbus/sync/snap/worker/db/hexary_error.nim

@@ -27,6 +27,10 @@ type
     TooManySlotAccounts
     NoAccountsYet
 
+    # range
+    LeafNodeExpected
+    FailedNextNode
+
     # nearby/boundary proofs
     NearbyExtensionError
     NearbyBranchError

nimbus/sync/snap/worker/db/hexary_import.nim

@@ -11,7 +11,6 @@
 import
   std/[sequtils, sets, strutils, tables],
   eth/[common, trie/nibbles],
-  stew/results,
   ../../range_desc,
   "."/[hexary_desc, hexary_error]
 

nimbus/sync/snap/worker/db/hexary_interpolate.nim

@@ -15,7 +15,7 @@
 ## re-factored database layer.
 
 import
-  std/[sequtils, sets, strutils, tables],
+  std/[sequtils, strutils, tables],
   eth/[common, trie/nibbles],
   stew/results,
   ../../range_desc,
@@ -508,10 +508,10 @@ proc rTreeSquashRootNode(
 # ------------------------------------------------------------------------------
 
 proc hexaryInterpolate*(
-    db: HexaryTreeDbRef;           ## Database
+    db: HexaryTreeDbRef;           # Database
-    rootKey: NodeKey;              ## Root node hash
+    rootKey: NodeKey;              # Root node hash
-    dbItems: var seq[RLeafSpecs];  ## List of path and leaf items
+    dbItems: var seq[RLeafSpecs];  # List of path and leaf items
-    bootstrap = false;             ## Can create root node on-the-fly
+    bootstrap = false;             # Can create root node on-the-fly
       ): Result[void,HexaryError]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## From the argument list `dbItems`, leaf nodes will be added to the hexary

nimbus/sync/snap/worker/db/hexary_nearby.nim

@@ -87,9 +87,9 @@ template noRlpErrorOops(info: static[string]; code: untyped) =
 # ------------------------------------------------------------------------------
 
 proc hexaryNearbyRightImpl(
-    baseTag: NodeTag;                 ## Some node
+    baseTag: NodeTag;                 # Some node
-    rootKey: NodeKey;                 ## State root
+    rootKey: NodeKey;                 # State root
-    db: HexaryTreeDbRef|HexaryGetFn;  ## Database abstraction
+    db: HexaryTreeDbRef|HexaryGetFn;  # Database abstraction
       ): Result[NodeTag,HexaryError]
       {.gcsafe, raises: [Defect,KeyError,RlpError]} =
   ## Wrapper
@@ -107,9 +107,9 @@ proc hexaryNearbyRightImpl(
   err(NearbyLeafExpected)
 
 proc hexaryNearbyLeftImpl(
-    baseTag: NodeTag;                 ## Some node
+    baseTag: NodeTag;                 # Some node
-    rootKey: NodeKey;                 ## State root
+    rootKey: NodeKey;                 # State root
-    db: HexaryTreeDbRef|HexaryGetFn;  ## Database abstraction
+    db: HexaryTreeDbRef|HexaryGetFn;  # Database abstraction
       ): Result[NodeTag,HexaryError]
       {.gcsafe, raises: [Defect,KeyError,RlpError]} =
   ## Wrapper
@@ -347,8 +347,8 @@ proc completeMost(
 # ------------------------------------------------------------------------------
 
 proc hexaryNearbyRight*(
-    path: RPath;                   ## Partially expanded path
+    path: RPath;                   # Partially expanded path
-    db: HexaryTreeDbRef;           ## Database
+    db: HexaryTreeDbRef;           # Database
       ): Result[RPath,HexaryError]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Extends the maximally extended argument nodes `path` to the right (i.e.
@@ -366,53 +366,72 @@ proc hexaryNearbyRight*(
   if path.path[^1].node.kind == Leaf:
     return ok(path)
 
-  var rPath = path
+  var
+    rPath = path
+    start = true
   while 0 < rPath.path.len:
     let top = rPath.path[^1]
-    if top.node.kind != Branch or
+    case top.node.kind:
-       top.nibble < 0 or
+    of Leaf:
-       rPath.tail.len == 0:
+      return err(NearbyUnexpectedNode)
-      return err(NearbyUnexpectedNode) # error
+    of Branch:
+      if top.nibble < 0 or rPath.tail.len == 0:
+        return err(NearbyUnexpectedNode)
+    of Extension:
+      rPath.tail = top.node.ePfx & rPath.tail
+      rPath.path.setLen(rPath.path.len - 1)
+      continue
 
-    let topLink = top.node.bLink[top.nibble]
+    var
-    if topLink.isZero or not db.tab.hasKey(topLink):
+      step = top
-      return err(NearbyDanglingLink) # error
+    let
+      rPathLen = rPath.path.len # in case of backtracking
+      rPathTail = rPath.tail    # in case of backtracking
 
-    let nextNibble = rPath.tail[0].int8
+    # Look ahead checking next node
-    if nextNibble < 15:
+    if start:
-      let
+      let topLink = top.node.bLink[top.nibble]
-        nextNode = db.tab[topLink]
+      if topLink.isZero or not db.tab.hasKey(topLink):
-        rPathLen = rPath.path.len # in case of backtracking
+        return err(NearbyDanglingLink) # error
-        rPathTail = rPath.tail
-      case nextNode.kind
-      of Leaf:
-        if rPath.tail <= nextNode.lPfx:
-          return rPath.completeLeast(topLink, db)
-      of Extension:
-        if rPath.tail <= nextNode.ePfx:
-          return rPath.completeLeast(topLink, db)
-      of Branch:
-        # Step down and complete with a branch link on the child node
-        rPath.path = rPath.path & RPathStep(
-          key:    topLink,
-          node:   nextNode,
-          nibble: nextNibble)
 
-      # Find the next item to the right of the new top entry
+      let nextNibble = rPath.tail[0].int8
-      let step = rPath.path[^1]
+      if start and nextNibble < 15:
-      for inx in (step.nibble + 1) .. 15:
+        let nextNode = db.tab[topLink]
-        let link = step.node.bLink[inx]
+        case nextNode.kind
-        if not link.isZero:
+        of Leaf:
-          rPath.path[^1].nibble = inx.int8
+          if rPath.tail <= nextNode.lPfx:
-          return rPath.completeLeast(link, db)
+            return rPath.completeLeast(topLink, db)
+        of Extension:
+          if rPath.tail <= nextNode.ePfx:
+            return rPath.completeLeast(topLink, db)
+        of Branch:
+          # Step down and complete with a branch link on the child node
+          step = RPathStep(
+            key:    topLink,
+            node:   nextNode,
+            nibble: nextNibble)
+          rPath.path &= step
 
-      # Restore `rPath` and backtrack
+    # Find the next item to the right of the current top entry
-      rPath.path.setLen(rPathLen)
+    for inx in (step.nibble + 1) .. 15:
-      rPath.tail = rPathTail
+      let link = step.node.bLink[inx]
+      if not link.isZero:
+        rPath.path[^1].nibble = inx.int8
+        return rPath.completeLeast(link, db)
 
-    # Pop `Branch` node on top and append nibble to `tail`
+    if start:
-    rPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & rPath.tail
+      # Retry without look ahead
-    rPath.path.setLen(rPath.path.len - 1)
+      start = false
+
+      # Restore `rPath` (pop temporary extra step)
+      if rPathLen < rPath.path.len:
+        rPath.path.setLen(rPathLen)
+        rPath.tail = rPathTail
+    else:
+      # Pop current `Branch` node on top and append nibble to `tail`
+      rPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & rPath.tail
+      rPath.path.setLen(rPath.path.len - 1)
+    # End while
 
   # Pathological case: nfffff.. for n < f
   var step = path.path[0]
@@ -425,10 +444,9 @@ proc hexaryNearbyRight*(
 
   err(NearbyFailed) # error
 
-
 proc hexaryNearbyRight*(
-    path: XPath;                   ## Partially expanded path
+    path: XPath;                   # Partially expanded path
-    getFn: HexaryGetFn;            ## Database abstraction
+    getFn: HexaryGetFn;            # Database abstraction
       ): Result[XPath,HexaryError]
       {.gcsafe, raises: [Defect,RlpError]} =
   ## Variant of `hexaryNearbyRight()` for persistant database
@@ -439,52 +457,71 @@ proc hexaryNearbyRight*(
   if path.path[^1].node.kind == Leaf:
     return ok(path)
 
-  var xPath = path
+  var
+    xPath = path
+    start = true
   while 0 < xPath.path.len:
     let top = xPath.path[^1]
-    if top.node.kind != Branch or
+    case top.node.kind:
-       top.nibble < 0 or
+    of Leaf:
-       xPath.tail.len == 0:
+      return err(NearbyUnexpectedNode)
-      return err(NearbyUnexpectedNode) # error
+    of Branch:
+      if top.nibble < 0 or xPath.tail.len == 0:
+        return err(NearbyUnexpectedNode)
+    of Extension:
+      xPath.tail = top.node.ePfx & xPath.tail
+      xPath.path.setLen(xPath.path.len - 1)
+      continue
 
-    let topLink = top.node.bLink[top.nibble]
+    var
-    if topLink.len == 0 or topLink.getFn().len == 0:
+      step = top
-      return err(NearbyDanglingLink) # error
+    let
+      xPathLen = xPath.path.len # in case of backtracking
+      xPathTail = xPath.tail    # in case of backtracking
 
-    let nextNibble = xPath.tail[0].int8
+    # Look ahead checking next node
-    if nextNibble < 15:
+    if start:
-      let
+      let topLink = top.node.bLink[top.nibble]
-        nextNodeRlp = rlpFromBytes topLink.getFn()
+      if topLink.len == 0 or topLink.getFn().len == 0:
-        xPathLen = xPath.path.len # in case of backtracking
+        return err(NearbyDanglingLink) # error
-        xPathTail = xPath.tail
-      case nextNodeRlp.listLen:
-      of 2:
-        if xPath.tail <= nextNodeRlp.listElem(0).toBytes.hexPrefixDecode[1]:
-          return xPath.completeLeast(topLink, getFn)
-      of 17:
-        # Step down and complete with a branch link on the child node
-        xPath.path = xPath.path & XPathStep(
-          key:    topLink,
-          node:   nextNodeRlp.toBranchNode,
-          nibble: nextNibble)
-      else:
-        return err(NearbyGarbledNode) # error
 
-      # Find the next item to the right of the new top entry
+      let nextNibble = xPath.tail[0].int8
-      let step = xPath.path[^1]
+      if nextNibble < 15:
-      for inx in (step.nibble + 1) .. 15:
+        let nextNodeRlp = rlpFromBytes topLink.getFn()
-        let link = step.node.bLink[inx]
+        case nextNodeRlp.listLen:
-        if 0 < link.len:
+        of 2:
-          xPath.path[^1].nibble = inx.int8
+          if xPath.tail <= nextNodeRlp.listElem(0).toBytes.hexPrefixDecode[1]:
-          return xPath.completeLeast(link, getFn)
+            return xPath.completeLeast(topLink, getFn)
+        of 17:
+          # Step down and complete with a branch link on the child node
+          step = XPathStep(
+            key:    topLink,
+            node:   nextNodeRlp.toBranchNode,
+            nibble: nextNibble)
+          xPath.path &= step
+        else:
+          return err(NearbyGarbledNode) # error
 
-      # Restore `xPath` and backtrack
+    # Find the next item to the right of the current top entry
-      xPath.path.setLen(xPathLen)
+    for inx in (step.nibble + 1) .. 15:
-      xPath.tail = xPathTail
+      let link = step.node.bLink[inx]
+      if 0 < link.len:
+        xPath.path[^1].nibble = inx.int8
+        return xPath.completeLeast(link, getFn)
 
-    # Pop `Branch` node on top and append nibble to `tail`
+    if start:
-    xPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & xPath.tail
+      # Retry without look ahead
-    xPath.path.setLen(xPath.path.len - 1)
+      start = false
+
+      # Restore `xPath` (pop temporary extra step)
+      if xPathLen < xPath.path.len:
+        xPath.path.setLen(xPathLen)
+        xPath.tail = xPathTail
+    else:
+      # Pop current `Branch` node on top and append nibble to `tail`
+      xPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & xPath.tail
+      xPath.path.setLen(xPath.path.len - 1)
+    # End while
 
   # Pathological case: nfffff.. for n < f
   var step = path.path[0]
@@ -537,8 +574,8 @@ proc hexaryNearbyRightMissing*(
 # ------------------------------------------------------------------------------
 
 proc hexaryNearbyLeft*(
-    path: RPath;                   ## Partially expanded path
+    path: RPath;                   # Partially expanded path
-    db: HexaryTreeDbRef;           ## Database
+    db: HexaryTreeDbRef;           # Database
       ): Result[RPath,HexaryError]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Similar to `hexaryNearbyRight()`.
@@ -552,53 +589,75 @@ proc hexaryNearbyLeft*(
   if path.path[^1].node.kind == Leaf:
     return ok(path)
 
-  var rPath = path
+  var
+    rPath = path
+    start = true
   while 0 < rPath.path.len:
     let top = rPath.path[^1]
-    if top.node.kind != Branch or
+    case top.node.kind:
-       top.nibble < 0 or
+    of Leaf:
-       rPath.tail.len == 0:
+      return err(NearbyUnexpectedNode)
-      return err(NearbyUnexpectedNode) # error
+    of Branch:
+      if top.nibble < 0 or rPath.tail.len == 0:
+        return err(NearbyUnexpectedNode)
+    of Extension:
+      rPath.tail = top.node.ePfx & rPath.tail
+      rPath.path.setLen(rPath.path.len - 1)
+      continue
 
-    let topLink = top.node.bLink[top.nibble]
+    var
-    if topLink.isZero or not db.tab.hasKey(topLink):
+      step = top
-      return err(NearbyDanglingLink) # error
+    let
+      rPathLen = rPath.path.len # in case of backtracking
+      rPathTail = rPath.tail    # in case of backtracking
 
-    let nextNibble = rPath.tail[0].int8
+    # Look ahead checking next node
-    if 0 < nextNibble:
+    if start:
-      let
+      let topLink = top.node.bLink[top.nibble]
-        nextNode = db.tab[topLink]
+      if topLink.isZero or not db.tab.hasKey(topLink):
-        rPathLen = rPath.path.len # in case of backtracking
+        return err(NearbyDanglingLink) # error
-        rPathTail = rPath.tail
-      case nextNode.kind
-      of Leaf:
-        if nextNode.lPfx <= rPath.tail:
-          return rPath.completeMost(topLink, db)
-      of Extension:
-        if nextNode.ePfx <= rPath.tail:
-          return rPath.completeMost(topLink, db)
-      of Branch:
-        # Step down and complete with a branch link on the child node
-        rPath.path = rPath.path & RPathStep(
-          key:    topLink,
-          node:   nextNode,
-          nibble: nextNibble)
 
-      # Find the next item to the right of the new top entry
+      let nextNibble = rPath.tail[0].int8
-      let step = rPath.path[^1]
+      if 0 < nextNibble:
-      for inx in (step.nibble - 1).countDown(0):
+        let
-        let link = step.node.bLink[inx]
+          nextNode = db.tab[topLink]
-        if not link.isZero:
+          rPathLen = rPath.path.len # in case of backtracking
-          rPath.path[^1].nibble = inx.int8
+          rPathTail = rPath.tail
-          return rPath.completeMost(link, db)
+        case nextNode.kind
+        of Leaf:
+          if nextNode.lPfx <= rPath.tail:
+            return rPath.completeMost(topLink, db)
+        of Extension:
+          if nextNode.ePfx <= rPath.tail:
+            return rPath.completeMost(topLink, db)
+        of Branch:
+          # Step down and complete with a branch link on the child node
+          step = RPathStep(
+            key:    topLink,
+            node:   nextNode,
+            nibble: nextNibble)
+          rPath.path &= step
 
-      # Restore `rPath` and backtrack
+    # Find the next item to the right of the new top entry
-      rPath.path.setLen(rPathLen)
+    for inx in (step.nibble - 1).countDown(0):
-      rPath.tail = rPathTail
+      let link = step.node.bLink[inx]
+      if not link.isZero:
+        rPath.path[^1].nibble = inx.int8
+        return rPath.completeMost(link, db)
 
-    # Pop `Branch` node on top and append nibble to `tail`
+    if start:
-    rPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & rPath.tail
+      # Retry without look ahead
-    rPath.path.setLen(rPath.path.len - 1)
+      start = false
+
+      # Restore `rPath` (pop temporary extra step)
+      if rPathLen < rPath.path.len:
+        rPath.path.setLen(rPathLen)
+        rPath.tail = rPathTail
+    else:
+      # Pop current `Branch` node on top and append nibble to `tail`
+      rPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & rPath.tail
+      rPath.path.setLen(rPath.path.len - 1)
+    # End while
 
   # Pathological case: n0000.. for 0 < n
   var step = path.path[0]
@@ -613,8 +672,8 @@ proc hexaryNearbyLeft*(
 
 
 proc hexaryNearbyLeft*(
-    path: XPath;                   ## Partially expanded path
+    path: XPath;                   # Partially expanded path
-    getFn: HexaryGetFn;            ## Database abstraction
+    getFn: HexaryGetFn;            # Database abstraction
       ): Result[XPath,HexaryError]
       {.gcsafe, raises: [Defect,RlpError]} =
   ## Variant of `hexaryNearbyLeft()` for persistant database
@@ -625,52 +684,74 @@ proc hexaryNearbyLeft*(
   if path.path[^1].node.kind == Leaf:
     return ok(path)
 
-  var xPath = path
+  var
+    xPath = path
+    start = true
   while 0 < xPath.path.len:
     let top = xPath.path[^1]
-    if top.node.kind != Branch or
+    case top.node.kind:
-       top.nibble < 0 or
+    of Leaf:
-       xPath.tail.len == 0:
+      return err(NearbyUnexpectedNode)
-      return err(NearbyUnexpectedNode) # error
+    of Branch:
+      if top.nibble < 0 or xPath.tail.len == 0:
+        return err(NearbyUnexpectedNode)
+    of Extension:
+      xPath.tail = top.node.ePfx & xPath.tail
+      xPath.path.setLen(xPath.path.len - 1)
+      continue
 
-    let topLink = top.node.bLink[top.nibble]
+    var
-    if topLink.len == 0 or topLink.getFn().len == 0:
+      step = top
-      return err(NearbyDanglingLink) # error
+    let
+      xPathLen = xPath.path.len # in case of backtracking
+      xPathTail = xPath.tail    # in case of backtracking
 
-    let nextNibble = xPath.tail[0].int8
+    # Look ahead checking next node
-    if 0 < nextNibble:
+    if start:
-      let
+      let topLink = top.node.bLink[top.nibble]
-        nextNodeRlp = rlpFromBytes topLink.getFn()
+      if topLink.len == 0 or topLink.getFn().len == 0:
-        xPathLen = xPath.path.len # in case of backtracking
+        return err(NearbyDanglingLink) # error
-        xPathTail = xPath.tail
-      case nextNodeRlp.listLen:
-      of 2:
-        if nextNodeRlp.listElem(0).toBytes.hexPrefixDecode[1] <= xPath.tail:
-          return xPath.completeMost(topLink, getFn)
-      of 17:
-        # Step down and complete with a branch link on the child node
-        xPath.path = xPath.path & XPathStep(
-          key:    topLink,
-          node:   nextNodeRlp.toBranchNode,
-          nibble: nextNibble)
-      else:
-        return err(NearbyGarbledNode) # error
 
-      # Find the next item to the right of the new top entry
+      let nextNibble = xPath.tail[0].int8
-      let step = xPath.path[^1]
+      if 0 < nextNibble:
-      for inx in (step.nibble - 1).countDown(0):
+        let
-        let link = step.node.bLink[inx]
+          nextNodeRlp = rlpFromBytes topLink.getFn()
-        if 0 < link.len:
+          xPathLen = xPath.path.len # in case of backtracking
-          xPath.path[^1].nibble = inx.int8
+          xPathTail = xPath.tail
-          return xPath.completeMost(link, getFn)
+        case nextNodeRlp.listLen:
+        of 2:
+          if nextNodeRlp.listElem(0).toBytes.hexPrefixDecode[1] <= xPath.tail:
+            return xPath.completeMost(topLink, getFn)
+        of 17:
+          # Step down and complete with a branch link on the child node
+          step = XPathStep(
+            key:    topLink,
+            node:   nextNodeRlp.toBranchNode,
+            nibble: nextNibble)
+          xPath.path &= step
+        else:
+          return err(NearbyGarbledNode) # error
 
-      # Restore `xPath` and backtrack
+    # Find the next item to the right of the new top entry
-      xPath.path.setLen(xPathLen)
+    for inx in (step.nibble - 1).countDown(0):
-      xPath.tail = xPathTail
+      let link = step.node.bLink[inx]
+      if 0 < link.len:
+        xPath.path[^1].nibble = inx.int8
+        return xPath.completeMost(link, getFn)
 
-    # Pop `Branch` node on top and append nibble to `tail`
+    if start:
-    xPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & xPath.tail
+      # Retry without look ahead
-    xPath.path.setLen(xPath.path.len - 1)
+      start = false
+
+      # Restore `xPath` (pop temporary extra step)
+      if xPathLen < xPath.path.len:
+        xPath.path.setLen(xPathLen)
+        xPath.tail = xPathTail
+    else:
+      # Pop `Branch` node on top and append nibble to `tail`
+      xPath.tail = @[top.nibble.byte].initNibbleRange.slice(1) & xPath.tail
+      xPath.path.setLen(xPath.path.len - 1)
+    # End while
 
   # Pathological case: n00000.. for 0 < n
   var step = path.path[0]
@@ -688,9 +769,9 @@ proc hexaryNearbyLeft*(
 # ------------------------------------------------------------------------------
 
 proc hexaryNearbyRight*(
-    baseTag: NodeTag;                 ## Some node
+    baseTag: NodeTag;                 # Some node
-    rootKey: NodeKey;                 ## State root
+    rootKey: NodeKey;                 # State root
-    db: HexaryTreeDbRef;              ## Database
+    db: HexaryTreeDbRef;              # Database
       ): Result[NodeTag,HexaryError]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Variant of `hexaryNearbyRight()` working with `NodeTag` arguments rather
@@ -699,9 +780,9 @@ proc hexaryNearbyRight*(
     return baseTag.hexaryNearbyRightImpl(rootKey, db)
 
 proc hexaryNearbyRight*(
-    baseTag: NodeTag;                 ## Some node
+    baseTag: NodeTag;                 # Some node
-    rootKey: NodeKey;                 ## State root
+    rootKey: NodeKey;                 # State root
-    getFn: HexaryGetFn;               ## Database abstraction
+    getFn: HexaryGetFn;               # Database abstraction
       ): Result[NodeTag,HexaryError]
       {.gcsafe, raises: [Defect,RlpError]} =
   ## Variant of `hexaryNearbyRight()` for persistant database
@@ -710,9 +791,9 @@ proc hexaryNearbyRight*(
 
 
 proc hexaryNearbyLeft*(
-    baseTag: NodeTag;                 ## Some node
+    baseTag: NodeTag;                 # Some node
-    rootKey: NodeKey;                 ## State root
+    rootKey: NodeKey;                 # State root
-    db: HexaryTreeDbRef;              ## Database
+    db: HexaryTreeDbRef;              # Database
       ): Result[NodeTag,HexaryError]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Similar to `hexaryNearbyRight()` for `NodeKey` arguments.
@@ -720,9 +801,9 @@ proc hexaryNearbyLeft*(
     return baseTag.hexaryNearbyLeftImpl(rootKey, db)
 
 proc hexaryNearbyLeft*(
-    baseTag: NodeTag;                 ## Some node
+    baseTag: NodeTag;                 # Some node
-    rootKey: NodeKey;                 ## State root
+    rootKey: NodeKey;                 # State root
-    getFn: HexaryGetFn;               ## Database abstraction
+    getFn: HexaryGetFn;               # Database abstraction
       ): Result[NodeTag,HexaryError]
       {.gcsafe, raises: [Defect,RlpError]} =
   ## Variant of `hexaryNearbyLeft()` for persistant database

nimbus/sync/snap/worker/db/hexary_paths.nim

@@ -420,9 +420,9 @@ proc leafData*(path: RPath): Blob =
 # ------------------------------------------------------------------------------
 
 proc hexaryPath*(
-    partialPath: NibblesSeq;        ## partial path to resolve
+    partialPath: NibblesSeq;        # partial path to resolve
-    rootKey: NodeKey|RepairKey;             ## State root
+    rootKey: NodeKey|RepairKey;     # State root
-    db: HexaryTreeDbRef;            ## Database
+    db: HexaryTreeDbRef;            # Database
       ): RPath
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Compute the longest possible repair tree `db` path matching the `nodeKey`
@@ -460,9 +460,9 @@ proc hexaryPath*(
 
 
 proc hexaryPath*(
-    partialPath: NibblesSeq;        ## partial path to resolve
+    partialPath: NibblesSeq;        # partial path to resolve
-    rootKey: NodeKey;               ## State root
+    rootKey: NodeKey;               # State root
-    getFn: HexaryGetFn;             ## Database abstraction
+    getFn: HexaryGetFn;             # Database abstraction
       ): XPath
       {.gcsafe, raises: [Defect,RlpError]} =
   ## Compute the longest possible path on an arbitrary hexary trie.
@@ -500,10 +500,10 @@ proc hexaryPath*(
 # ------------------------------------------------------------------------------
 
 proc hexaryPathNodeKey*(
-    partialPath: NibblesSeq;       ## Hex encoded partial path
+    partialPath: NibblesSeq;       # Hex encoded partial path
-    rootKey: NodeKey|RepairKey;    ## State root
+    rootKey: NodeKey|RepairKey;    # State root
-    db: HexaryTreeDbRef;           ## Database
+    db: HexaryTreeDbRef;           # Database
-    missingOk = false;             ## Also return key for missing node
+    missingOk = false;             # Also return key for missing node
       ): Result[NodeKey,void]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Returns the `NodeKey` equivalent for the argment `partialPath` if this
@@ -524,10 +524,10 @@ proc hexaryPathNodeKey*(
   err()
 
 proc hexaryPathNodeKey*(
-    partialPath: Blob;             ## Hex encoded partial path
+    partialPath: Blob;             # Hex encoded partial path
-    rootKey: NodeKey|RepairKey;    ## State root
+    rootKey: NodeKey|RepairKey;    # State root
-    db: HexaryTreeDbRef;           ## Database
+    db: HexaryTreeDbRef;           # Database
-    missingOk = false;             ## Also return key for missing node
+    missingOk = false;             # Also return key for missing node
       ): Result[NodeKey,void]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Variant of `hexaryPathNodeKey()` for hex encoded partial path.
@@ -535,10 +535,10 @@ proc hexaryPathNodeKey*(
 
 
 proc hexaryPathNodeKey*(
-    partialPath: NibblesSeq;       ## Hex encoded partial path
+    partialPath: NibblesSeq;       # Hex encoded partial path
-    rootKey: NodeKey;              ## State root
+    rootKey: NodeKey;              # State root
-    getFn: HexaryGetFn;            ## Database abstraction
+    getFn: HexaryGetFn;            # Database abstraction
-    missingOk = false;             ## Also return key for missing node
+    missingOk = false;             # Also return key for missing node
       ): Result[NodeKey,void]
       {.gcsafe, raises: [Defect,RlpError]} =
   ## Variant of `hexaryPathNodeKey()` for persistent database.
@@ -556,10 +556,10 @@ proc hexaryPathNodeKey*(
   err()
 
 proc hexaryPathNodeKey*(
-    partialPath: Blob;             ## Partial database path
+    partialPath: Blob;             # Partial database path
-    rootKey: NodeKey;              ## State root
+    rootKey: NodeKey;              # State root
-    getFn: HexaryGetFn;            ## Database abstraction
+    getFn: HexaryGetFn;            # Database abstraction
-    missingOk = false;             ## Also return key for missing node
+    missingOk = false;             # Also return key for missing node
       ): Result[NodeKey,void]
       {.gcsafe, raises: [Defect,RlpError]} =
   ## Variant of `hexaryPathNodeKey()` for persistent database and
@@ -568,10 +568,10 @@ proc hexaryPathNodeKey*(
 
 
 proc hexaryPathNodeKeys*(
-    partialPaths: seq[Blob];       ## Partial paths segments
+    partialPaths: seq[Blob];       # Partial paths segments
-    rootKey: NodeKey|RepairKey;    ## State root
+    rootKey: NodeKey|RepairKey;    # State root
-    db: HexaryTreeDbRef;           ## Database
+    db: HexaryTreeDbRef;           # Database
-    missingOk = false;             ## Also return key for missing node
+    missingOk = false;             # Also return key for missing node
       ): HashSet[NodeKey]
       {.gcsafe, raises: [Defect,KeyError]} =
   ## Convert a list of path segments to a set of node keys

nimbus/sync/snap/worker/db/hexary_range.nim

@@ -0,0 +1,173 @@
+# nimbus-eth1
+# Copyright (c) 2021 Status Research & Development GmbH
+# Licensed under either of
+#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+#    http://www.apache.org/licenses/LICENSE-2.0)
+#  * MIT license ([LICENSE-MIT](LICENSE-MIT) or
+#    http://opensource.org/licenses/MIT)
+# at your option. This file may not be copied, modified, or distributed
+# except according to those terms.
+
+import
+  std/[sequtils, sets, tables],
+  chronicles,
+  eth/[common, p2p, rlp, trie/nibbles],
+  stew/[byteutils, interval_set],
+  ../../range_desc,
+  "."/[hexary_desc, hexary_error, hexary_nearby, hexary_paths]
+
+{.push raises: [Defect].}
+
+type
+  RangeLeaf* = object
+    key*: NodeKey ## Leaf node path
+    data*: Blob   ## Leaf node data
+
+  RangeProof* = object
+    leafs*: seq[RangeLeaf]
+    proof*: seq[Blob]
+
+# ------------------------------------------------------------------------------
+# Private helpers
+# ------------------------------------------------------------------------------
+
+proc convertTo(key: RepairKey; T: type NodeKey): T =
+  ## Might be lossy, check before use (if at all, unless debugging)
+  (addr result.ByteArray32[0]).copyMem(unsafeAddr key.ByteArray33[1], 32)
+
+# ------------------------------------------------------------------------------
+# Private functions
+# ------------------------------------------------------------------------------
+
+template collectLeafs(
+    iv: NodeTagRange;                # Proofed range of leaf paths
+    rootKey: NodeKey|RepairKey;      # State root
+    db: HexaryGetFn|HexaryTreeDbRef; # Database abstraction
+    nLeafs: int;                     # Implies maximal data size
+      ): auto =
+  ## Collect trie database leafs prototype. This directive is provided as
+  ## `template` for avoiding varying exceprion annotations.
+  var rc: Result[seq[RangeLeaf],HexaryError]
+
+  block body:
+    var
+      nodeTag = iv.minPt
+      prevTag: NodeTag
+      rls: seq[RangeLeaf]
+
+    # Fill at most `nLeafs` leaf nodes from interval range
+    while rls.len < nLeafs and nodeTag <= iv.maxPt:
+      # The following logic might be sub-optimal. A strict version of the
+      # `next()` function that stops with an error at dangling links could
+      # be faster if the leaf nodes are not too far apart on the hexary trie.
+      var
+        xPath = block:
+          let rx = nodeTag.hexaryPath(rootKey,db).hexaryNearbyRight(db)
+          if rx.isErr:
+            rc = typeof(rc).err(rx.error)
+            break body
+          rx.value
+        rightKey = xPath.getPartialPath.convertTo(NodeKey)
+        rightTag = rightKey.to(NodeTag)
+
+      # Prevents from semi-endless looping
+      if rightTag <= prevTag and 0 < rls.len:
+        # Oops, should have been tackeled by `hexaryNearbyRight()`
+        rc = typeof(rc).err(FailedNextNode)
+        break body # stop here
+
+      rls.add RangeLeaf(
+        key:  rightKey,
+        data: xPath.leafData)
+
+      prevTag = nodeTag
+      nodeTag = rightTag + 1.u256
+
+    rc = typeof(rc).ok(rls)
+    # End body
+
+  rc
+
+
+template updateProof(
+    baseTag: NodeTag;                # Left boundary
+    leafList: seq[RangeLeaf];        # Set of collected leafs
+    rootKey: NodeKey|RepairKey;      # State root
+    db: HexaryGetFn|HexaryTreeDbRef; # Database abstraction
+      ): auto =
+  ## Update leafs list by adding proof nodes. This directive is provided as
+  ## `template` for avoiding varying exceprion annotations.
+  var proof = baseTag.hexaryPath(rootKey, db)
+        .path
+        .mapIt(it.node)
+        .filterIt(it.kind != Leaf)
+        .mapIt(it.convertTo(Blob))
+        .toHashSet
+  if 0 < leafList.len:
+    proof.incl leafList[^1].key.to(NodeTag).hexaryPath(rootKey, db)
+        .path
+         .mapIt(it.node)
+        .filterIt(it.kind != Leaf)
+        .mapIt(it.convertTo(Blob))
+        .toHashSet
+
+  RangeProof(
+    leafs: leafList,
+    proof: proof.toSeq)
+
+# ------------------------------------------------------------------------------
+# Public functions
+# ------------------------------------------------------------------------------
+
+proc hexaryRangeLeafsProof*(
+    iv: NodeTagRange;                # Proofed range of leaf paths
+    rootKey: NodeKey;                # State root
+    db: HexaryGetFn;                 # Database abstraction
+    nLeafs = high(int);              # Implies maximal data size
+      ): Result[RangeProof,HexaryError]
+      {.gcsafe, raises: [Defect,RlpError]} =
+  ## ...
+  let rc = iv.collectLeafs(rootKey, db, nLeafs)
+  if rc.isErr:
+    err(rc.error)
+  else:
+    ok(iv.minPt.updateProof(rc.value, rootKey, db))
+
+proc hexaryRangeLeafsProof*(
+    baseTag: NodeTag;                # Left boundary
+    leafList: seq[RangeLeaf];        # Set of already collected leafs
+    rootKey: NodeKey;                # State root
+    db: HexaryGetFn;                 # Database abstraction
+      ): RangeProof
+      {.gcsafe, raises: [Defect,RlpError]} =
+  ## ...
+  baseTag.updateProof(leafList, rootKey, db)
+
+
+proc hexaryRangeLeafsProof*(
+    iv: NodeTagRange;                # Proofed range of leaf paths
+    rootKey: NodeKey;                # State root
+    db: HexaryTreeDbRef;             # Database abstraction
+    nLeafs = high(int);              # Implies maximal data size
+      ): Result[RangeProof,HexaryError]
+      {.gcsafe, raises: [Defect,KeyError]} =
+  ## ...
+  let rc = iv.collectLeafs(rootKey, db, nLeafs)
+  if rc.isErr:
+    err(rc.error)
+  else:
+    ok(iv.minPt.updateProof(rc.value, rootKey, db))
+
+proc hexaryRangeLeafsProof*(
+    baseTag: NodeTag;                # Left boundary
+    leafList: seq[RangeLeaf];        # Set of already collected leafs
+    rootKey: NodeKey;                # State root
+    db: HexaryTreeDbRef;             # Database abstraction
+      ): RangeProof
+      {.gcsafe, raises: [Defect,KeyError]} =
+  ## ...
+  baseTag.updateProof(leafList, rootKey, db)
+
+# ------------------------------------------------------------------------------
+# End
+# ------------------------------------------------------------------------------

nimbus/sync/snap/worker/db/snapdb_desc.nim

@@ -322,7 +322,7 @@ proc dumpPath*(ps: SnapDbBaseRef; key: NodeTag): seq[string] =
     let rPath= key.hexaryPath(ps.root, ps.hexaDb)
     result = rPath.path.mapIt(it.pp(ps.hexaDb)) & @["(" & rPath.tail.pp & ")"]
 
-proc dumpHexaDB*(ps: SnapDbBaseRef; indent = 4): string =
+proc dumpHexaDB*(xDb: HexaryTreeDbRef; root: NodeKey; indent = 4): string =
   ## Dump the entries from the a generic accounts trie. These are
   ## key value pairs for
   ## ::
@@ -348,7 +348,11 @@ proc dumpHexaDB*(ps: SnapDbBaseRef; indent = 4): string =
   ## added later (typically these nodes are update `Mutable` nodes.)
   ##
   ## Beware: dumping a large database is not recommended
-  ps.hexaDb.pp(ps.root,indent)
+  xDb.pp(root, indent)
+
+proc dumpHexaDB*(ps: SnapDbBaseRef; indent = 4): string =
+  ## Ditto
+  ps.hexaDb.pp(ps.root, indent)
 
 proc hexaryPpFn*(ps: SnapDbBaseRef): HexaryPpFn =
   ## Key mapping function used in `HexaryTreeDB`

nimbus/sync/snap/worker/pivot.nim

@@ -9,7 +9,7 @@
 # except according to those terms.
 
 import
-  std/[math, sets, sequtils, strutils],
+  std/[math, sets, sequtils],
   chronicles,
   chronos,
   eth/[common, p2p, trie/trie_defs],

tests/replay/gunzip.nim

@@ -119,7 +119,7 @@ proc open*(state: var GUnzip; fileName: string):
   state.gzIn = fileName.open(fmRead)
   state.gzOpenOK = true
   state.gzMax = state.gzIn.getFileSize
-  state.gzCount = state.gzIn.readChars(strBuf, 0, strBuf.len)
+  state.gzCount = state.gzIn.readChars(toOpenArray(strBuf, 0, strBuf.len-1))
 
   # Parse GZIP header (RFC 1952)
   doAssert 18 < state.gzCount
@@ -157,7 +157,7 @@ proc nextChunk*(state: var GUnzip):
   result = ok("")
 
   while state.gzCount < state.gzMax:
-    var strLen = state.gzIn.readChars(strBuf, 0, strBuf.len)
+    var strLen = state.gzIn.readChars(toOpenArray(strBuf, 0, strBuf.len-1))
     if state.gzMax < state.gzCount + strLen:
       strLen = (state.gzMax - state.gzCount).int
     state.gzCount += strLen

tests/test_sync_snap.nim

@@ -27,8 +27,8 @@ import
   ./replay/[pp, undump_accounts, undump_storages],
   ./test_sync_snap/[
     bulk_test_xx, snap_test_xx,
-    test_accounts, test_node_range, test_inspect, test_pivot, test_storage,
+    test_accounts, test_helpers, test_node_range, test_inspect, test_pivot,
-    test_db_timing, test_types]
+    test_storage, test_db_timing, test_types]
 
 const
   baseDir = [".", "..", ".."/"..", $DirSep]
@@ -61,9 +61,6 @@ else:
   const isUbuntu32bit = false
 
 let
-  # Forces `check()` to print the error (as opposed when using `isOk()`)
-  OkHexDb = Result[void,HexaryError].ok()
-
   # There was a problem with the Github/CI which results in spurious crashes
   # when leaving the `runner()` if the persistent ChainDBRef initialisation
   # was present, see `test_custom_network` for more details.
@@ -92,15 +89,6 @@ proc findFilePath(file: string;
 proc getTmpDir(sampleDir = sampleDirRefFile): string =
   sampleDir.findFilePath(baseDir,repoDir).value.splitFile.dir
 
-proc say*(noisy = false; pfx = "***"; args: varargs[string, `$`]) =
-  if noisy:
-    if args.len == 0:
-      echo "*** ", pfx
-    elif 0 < pfx.len and pfx[^1] != ' ':
-      echo pfx, " ", args.toSeq.join
-    else:
-      echo pfx, args.toSeq.join
-
 proc setTraceLevel =
   discard
   when defined(chronicles_runtime_filtering) and loggingEnabled:
@@ -176,9 +164,6 @@ proc testDbs(workDir = ""; subDir = ""; instances = nTestDbInstances): TestDbs =
     for n in 0 ..< min(result.cdb.len, instances):
       result.cdb[n] = (result.dbDir / $n).newChainDB
 
-proc lastTwo(a: openArray[string]): seq[string] =
-  if 1 < a.len: @[a[^2],a[^1]] else: a.toSeq
-
 proc snapDbRef(cdb: ChainDb; pers: bool): SnapDbRef =
   if pers: SnapDbRef.init(cdb) else: SnapDbRef.init(newMemoryDB())
 
@@ -209,22 +194,43 @@ proc accountsRunner(noisy = true;  persistent = true; sample = accSample) =
       tmpDir.flushDbDir(sample.name)
 
   suite &"SyncSnap: {fileInfo} accounts and proofs for {info}":
-    test &"Proofing {accLst.len} items for state root ..{root.pp}":
-      let desc = db.cdb[0].snapDbAccountsRef(root, db.persistent)
-      accLst.test_accountsImport(desc, db.persistent)
-
-    var accKeys: seq[NodeKey]
 
     block:
+      # New common descriptor for this sub-group of tests
       let
-        # Common descriptor for this group of tests
+        desc = db.cdb[0].snapDbAccountsRef(root, db.persistent)
-        desc = db.cdb[1].snapDbAccountsRef(root, db.persistent)
+        hexaDb = desc.hexaDb
+        getFn = desc.getAccountFn
+        dbg = if noisy: hexaDb else: nil
 
-        # Database abstractions
+      desc.assignPrettyKeys() # debugging, make sure that state root ~ "$0"
-        getFn = desc.getAccountFn # pestistent case
-        hexaDB = desc.hexaDB      # in-memory, and debugging setup
 
-      test &"Merging {accLst.len} proofs for state root ..{root.pp}":
+      test &"Proofing {accLst.len} list items for state root ..{root.pp}":
+        accLst.test_accountsImport(desc, db.persistent)
+
+      test &"Retrieve accounts & proofs for previous account ranges":
+        let nPart = 3
+        if db.persistent:
+          accLst.test_NodeRangeRightProofs(getFn, nPart, dbg)
+        else:
+          accLst.test_NodeRangeRightProofs(hexaDB, nPart, dbg)
+
+      test &"Verify left boundary checks":
+        if db.persistent:
+          accLst.test_NodeRangeLeftBoundary(getFn, dbg)
+        else:
+          accLst.test_NodeRangeLeftBoundary(hexaDB, dbg)
+
+    block:
+      # List of keys to be shared by sub-group
+      var accKeys: seq[NodeKey]
+
+      # New common descriptor for this sub-group of tests
+      let
+        cdb = db.cdb[1]
+        desc = cdb.snapDbAccountsRef(root, db.persistent)
+
+      test &"Merging {accLst.len} accounts/proofs lists into single list":
         accLst.test_accountsMergeProofs(desc, accKeys) # set up `accKeys`
 
       test &"Revisiting {accKeys.len} stored items on ChainDBRef":
@@ -233,17 +239,19 @@ proc accountsRunner(noisy = true;  persistent = true; sample = accSample) =
         # true.say "***", "database dump\n    ", desc.dumpHexaDB()
 
       test &"Decompose path prefix envelopes on {info}":
+        let hexaDb = desc.hexaDb
         if db.persistent:
-          accKeys.test_NodeRangeDecompose(root, getFn, hexaDB)
+          accKeys.test_NodeRangeDecompose(root, desc.getAccountFn, hexaDb)
         else:
-          accKeys.test_NodeRangeDecompose(root, hexaDB, hexaDB)
+          accKeys.test_NodeRangeDecompose(root, hexaDb, hexaDb)
+
+      test &"Storing/retrieving {accKeys.len} stored items " &
+          "on persistent pivot/checkpoint registry":
+        if db.persistent:
+          accKeys.test_pivotStoreRead(cdb)
+        else:
+          skip()
 
-    test &"Storing/retrieving {accKeys.len} items " &
-        "on persistent pivot/checkpoint registry":
-      if db.persistent:
-        accKeys.test_pivotStoreRead(db.cdb[0])
-      else:
-        skip()
 
 proc storagesRunner(
     noisy = true;
@@ -539,14 +547,14 @@ when isMainModule:
   #
 
   # This one uses dumps from the external `nimbus-eth1-blob` repo
-  when true and false:
+  when true: # and false:
     import ./test_sync_snap/snap_other_xx
     noisy.showElapsed("accountsRunner()"):
       for n,sam in snapOtherList:
         false.accountsRunner(persistent=true, sam)
-    noisy.showElapsed("inspectRunner()"):
+    #noisy.showElapsed("inspectRunner()"):
-      for n,sam in snapOtherHealingList:
+    #  for n,sam in snapOtherHealingList:
-        false.inspectionRunner(persistent=true, cascaded=false, sam)
+    #    false.inspectionRunner(persistent=true, cascaded=false, sam)
 
   # This one usues dumps from the external `nimbus-eth1-blob` repo
   when true and false:
@@ -564,14 +572,14 @@ when isMainModule:
 
   # This one uses readily available dumps
   when true: # and false:
-    false.inspectionRunner()
+  #  false.inspectionRunner()
     for n,sam in snapTestList:
       false.accountsRunner(persistent=false, sam)
       false.accountsRunner(persistent=true, sam)
     for n,sam in snapTestStorageList:
       false.accountsRunner(persistent=false, sam)
       false.accountsRunner(persistent=true, sam)
-      false.storagesRunner(persistent=true, sam)
+  #    false.storagesRunner(persistent=true, sam)
 
   # This one uses readily available dumps
   when true and false:

tests/test_sync_snap/test_accounts.nim

@@ -12,8 +12,8 @@
 ## Snap sync components tester and TDD environment
 
 import
-  std/[algorithm, sequtils, strformat, strutils, tables],
+  std/algorithm,
-  eth/[common, p2p, trie/db],
+  eth/[common, p2p],
   unittest2,
   ../../nimbus/db/select_backend,
   ../../nimbus/sync/snap/range_desc,
@@ -36,7 +36,7 @@ proc flatten(list: openArray[seq[Blob]]): seq[Blob] =
 proc test_accountsImport*(
     inList: seq[UndumpAccounts];
     desc: SnapDbAccountsRef;
-    persistent: bool
+    persistent: bool;
       ) =
   ## Import accounts
   for n,w in inList:

tests/test_sync_snap/test_db_timing.nim

@@ -12,7 +12,7 @@
 ## Snap sync components tester and TDD environment
 
 import
-  std/[algorithm, math, sequtils, strformat, strutils, times],
+  std/[algorithm, math, sequtils, strformat, times],
   stew/byteutils,
   rocksdb,
   unittest2,

tests/test_sync_snap/test_helpers.nim

@@ -12,7 +12,7 @@
 import
   std/times,
   eth/common,
-  stew/results,
+  stew/[interval_set, results],
   unittest2,
   ../../nimbus/sync/snap/range_desc,
   ../../nimbus/sync/snap/worker/db/hexary_error,
@@ -31,6 +31,9 @@ proc isImportOk*(rc: Result[SnapAccountsGaps,HexaryError]): bool =
   else:
     return true
 
+proc lastTwo*(a: openArray[string]): seq[string] =
+  if 1 < a.len: @[a[^2],a[^1]] else: a.toSeq
+
 # ------------------------------------------------------------------------------
 # Public type conversions
 # ------------------------------------------------------------------------------
@@ -63,6 +66,12 @@ proc to*(w: (byte, NodeTag); T: type Blob): T =
 proc to*(t: NodeTag; T: type Blob): T =
   toSeq(t.UInt256.toBytesBE)
 
+# ----------
+
+proc convertTo*(key: RepairKey; T: type NodeKey): T =
+  ## Might be lossy, check before use (if at all, unless debugging)
+  (addr result.ByteArray32[0]).copyMem(unsafeAddr key.ByteArray33[1], 32)
+
 # ------------------------------------------------------------------------------
 # Public functions, pretty printing
 # ------------------------------------------------------------------------------
@@ -95,6 +104,27 @@ proc say*(noisy = false; pfx = "***"; args: varargs[string, `$`]) =
     else:
       echo pfx, args.toSeq.join
 
+# ------------------------------------------------------------------------------
+# Public free parking
+# ------------------------------------------------------------------------------
+
+proc rangeAccountSizeMax*(n: int): int =
+  ## Max number of bytes needed to store `n` RLP encoded `Account()` type
+  ## entries. Note that this is an upper bound.
+  ##
+  ## The maximum size of a single RLP encoded account item can be determined
+  ## by setting every field of `Account()` to `high()` or `0xff`.
+  if 127 < n:
+    3 + n * 110
+  elif 0 < n:
+    2 + n * 110
+  else:
+    1
+
+proc rangeNumAccounts*(size: int): int =
+  ## ..
+  (size - 3) div 110
+
 # ------------------------------------------------------------------------------
 # End
 # ------------------------------------------------------------------------------

tests/test_sync_snap/test_inspect.nim

@@ -12,7 +12,7 @@
 ## Snap sync components tester and TDD environment
 
 import
-  std/[sequtils, strformat, strutils],
+  std/[sequtils],
   eth/[common, p2p, trie/db],
   unittest2,
   ../../nimbus/db/select_backend,

tests/test_sync_snap/test_node_range.nim

@@ -13,12 +13,16 @@
 
 import
   std/[sequtils, strformat, strutils],
-  eth/[common, p2p, trie/nibbles],
+  eth/[common, p2p, rlp, trie/nibbles],
   stew/[byteutils, interval_set, results],
   unittest2,
+  ../../nimbus/sync/types,
   ../../nimbus/sync/snap/range_desc,
   ../../nimbus/sync/snap/worker/db/[
-    hexary_desc, hexary_envelope, hexary_nearby, hexary_paths]
+    hexary_desc, hexary_envelope,  hexary_error, hexary_nearby, hexary_paths,
+    hexary_range, snapdb_accounts, snapdb_desc],
+  ../replay/[pp, undump_accounts],
+  ./test_helpers
 
 const
   cmaNlSp0 = ",\n" & repeat(" ",12)
@@ -78,6 +82,125 @@ proc print_data(
     "\n    pfxMax=", pfx.hexaryEnvelope.maxPt,
     "\n    ", pfx.hexaryEnvelope.maxPt.hexaryPath(rootKey,db).pp(dbg)
 
+
+proc printCompareRightLeafs(
+    rootKey: NodeKey;
+    baseTag: NodeTag;
+    accounts: seq[PackedAccount];
+    leafs: seq[RangeLeaf];
+    db: HexaryTreeDbRef|HexaryGetFn;        ## Database abstraction
+    dbg: HexaryTreeDbRef;                   ## Debugging env
+      ) =
+  let
+    noisy = not dbg.isNil
+  var
+    top = 0
+    nMax = min(accounts.len, leafs.len)
+    step = nMax div 2
+
+  while top < nMax:
+    while 1 < step and accounts[top+step].accKey != leafs[top+step].key:
+      #noisy.say "***", "i=", top+step, " fail"
+      step = max(1, step div 2)
+
+    if accounts[top+step].accKey == leafs[top+step].key:
+      top += step
+      step = max(1, step div 2)
+      noisy.say "***", "i=", top, " step=", step, " ok"
+      continue
+
+    let start = top
+    top = nMax
+    for i in start ..< top:
+      if accounts[i].accKey == leafs[i].key:
+        noisy.say "***", "i=", i, " skip, ok"
+        continue
+
+      # Diagnostics and return
+      check (i,accounts[i].accKey) == (i,leafs[i].key)
+
+      let
+        lfsKey = leafs[i].key
+        accKey = accounts[i].accKey
+        prdKey = if 0 < i: accounts[i-1].accKey else: baseTag.to(NodeKey)
+        nxtTag = if 0 < i: prdKey.to(NodeTag) + 1.u256 else: baseTag
+        nxtPath = nxtTag.hexaryPath(rootKey,db)
+        rightRc = nxtPath.hexaryNearbyRight(db)
+
+      if rightRc.isOk:
+        check lfsKey == rightRc.value.getPartialPath.convertTo(NodeKey)
+      else:
+        check rightRc.error == HexaryError(0) # force error printing
+
+      noisy.say "\n***", "i=", i, "/", accounts.len,
+        "\n",
+        "\n    prdKey=", prdKey,
+        "\n    ", prdKey.hexaryPath(rootKey,db).pp(dbg),
+        "\n",
+        "\n    nxtKey=", nxtTag,
+        "\n    ", nxtPath.pp(dbg),
+        "\n",
+        "\n    accKey=", accKey,
+        "\n    ", accKey.hexaryPath(rootKey,db).pp(dbg),
+        "\n",
+        "\n    lfsKey=", lfsKey,
+        "\n    ", lfsKey.hexaryPath(rootKey,db).pp(dbg),
+        "\n"
+      return
+
+
+proc printCompareLeftNearby(
+    rootKey: NodeKey;
+    leftKey: NodeKey;
+    rightKey: NodeKey;
+    db: HexaryTreeDbRef|HexaryGetFn;        ## Database abstraction
+    dbg: HexaryTreeDbRef;                   ## Debugging env
+      ) =
+  let
+    noisy = not dbg.isNil
+    rightPath = rightKey.hexaryPath(rootKey,db)
+    toLeftRc = rightPath.hexaryNearbyLeft(db)
+  var
+    toLeftKey: NodeKey
+
+  if toLeftRc.isErr:
+    check toLeftRc.error == HexaryError(0) # force error printing
+  else:
+    toLeftKey = toLeftRc.value.getPartialPath.convertTo(NodeKey)
+    if toLeftKey == leftKey:
+      return
+
+  noisy.say "\n***",
+    "    rightKey=", rightKey,
+    "\n    ", rightKey.hexaryPath(rootKey,db).pp(dbg),
+    "\n",
+    "\n    leftKey=", leftKey,
+    "\n    ", leftKey.hexaryPath(rootKey,db).pp(dbg),
+    "\n",
+    "\n    toLeftKey=", toLeftKey,
+    "\n    ", toLeftKey.hexaryPath(rootKey,db).pp(dbg),
+    "\n"
+
+
+proc verifyAccountListSizes() =
+  ## RLP does not allow static check ..
+  for n in [0, 1, 128, 129, 200]:
+    check n.rangeAccountSizeMax == Account(
+      storageRoot: Hash256(data: high(UInt256).toBytesBE),
+      codeHash:    Hash256(data: high(UInt256).toBytesBE),
+      nonce:       high(uint64),
+      balance:     high(UInt256)).repeat(n).encode.len
+
+# ------------------------------------------------------------------------------
+# Private functions, pretty printing
+# ------------------------------------------------------------------------------
+
+proc pp(a: NodeTag; collapse = true): string =
+  a.to(NodeKey).pp(collapse)
+
+proc pp(iv: NodeTagRange; collapse = false): string =
+  "(" & iv.minPt.pp(collapse) & "," & iv.maxPt.pp(collapse) & ")"
+
 # ------------------------------------------------------------------------------
 # Public test function
 # ------------------------------------------------------------------------------
@@ -198,6 +321,78 @@ proc test_NodeRangeDecompose*(
 
       if true: quit()
 
+
+proc test_NodeRangeRightProofs*(
+    inLst: seq[UndumpAccounts];
+    db: HexaryTreeDbRef|HexaryGetFn;         ## Database abstraction
+    nSplit = 0;                              ## Also split intervals (unused)
+    dbg = HexaryTreeDbRef(nil);              ## Debugging env
+      ) =
+  ## Partition range and provide proofs suitable for `GetAccountRange` message
+  ## from `snap/1` protocol.
+  let
+    rootKey = inLst[0].root.to(NodeKey)
+    noisy = not dbg.isNil
+
+  # RLP does not allow static check
+  verifyAccountListSizes()
+
+  # Assuming the `inLst` entries have been stored in the DB already
+  for n,w in inLst:
+    let
+      iv = NodeTagRange.new(w.base, w.data.accounts[^1].accKey.to(NodeTag))
+      rc = iv.hexaryRangeLeafsProof(rootKey, db, high(int))
+    check rc.isOk
+    if rc.isErr:
+      return
+
+    let
+      leafs = rc.value.leafs
+      accounts = w.data.accounts
+    if leafs.len != accounts.len or accounts[^1].accKey != leafs[^1].key:
+      noisy.say "***", "n=", n, " something went wrong .."
+      check (n,leafs.len) == (n,accounts.len)
+      rootKey.printCompareRightLeafs(w.base, accounts, leafs, db, dbg)
+      return
+
+    # FIXME: verify that proof nodes are complete
+
+    check rc.value.proof.len <= w.data.proof.len
+    check leafs[^1].key.to(NodeTag) <= iv.maxPt
+    noisy.say "***", "n=", n,
+      " leafs=", leafs.len,
+      " proof=", rc.value.proof.len, "/", w.data.proof.len
+
+
+proc test_NodeRangeLeftBoundary*(
+    inLst: seq[UndumpAccounts];
+    db: HexaryTreeDbRef|HexaryGetFn;         ## Database abstraction
+    dbg = HexaryTreeDbRef(nil);              ## Debugging env
+      ) =
+  ## Verify left side boundary checks
+  let
+    rootKey = inLst[0].root.to(NodeKey)
+    noisy = not dbg.isNil
+
+  # Assuming the `inLst` entries have been stored in the DB already
+  for n,w in inLst:
+    let accounts = w.data.accounts
+    for i in 1 ..< accounts.len:
+      let
+        leftKey = accounts[i-1].accKey
+        rightKey = (accounts[i].accKey.to(NodeTag) - 1.u256).to(NodeKey)
+        toLeftRc = rightKey.hexaryPath(rootKey,db).hexaryNearbyLeft(db)
+      if toLeftRc.isErr:
+        check toLeftRc.error == HexaryError(0) # force error printing
+        return
+      let toLeftKey = toLeftRc.value.getPartialPath.convertTo(NodeKey)
+      if leftKey != toLeftKey:
+        let j = i-1
+        check (n, j, leftKey) == (n, j, toLeftKey)
+        rootKey.printCompareLeftNearby(leftKey, rightKey, db, dbg)
+        return
+    noisy.say "***", "n=", n, " accounts=", accounts.len
+
 # ------------------------------------------------------------------------------
 # End
 # ------------------------------------------------------------------------------

tests/test_sync_snap/test_pivot.nim

@@ -12,7 +12,6 @@
 ## Snap sync components tester and TDD environment
 
 import
-  std/[sequtils, strformat, strutils],
   eth/[common, p2p],
   unittest2,
   ../../nimbus/db/select_backend,
@@ -34,7 +33,8 @@ proc test_pivotStoreRead*(
                   (4.to(NodeTag),5.to(NodeTag)),
                   (6.to(NodeTag),7.to(NodeTag))]
     slotAccounts = seq[NodeKey].default
-  for n,w in accKeys:
+  for n in 0 ..< accKeys.len:
+    let w = accKeys[n]
     check dbBase.savePivot(
       SnapDbPivotRegistry(
         header:       BlockHeader(stateRoot: w.to(Hash256)),
@@ -50,7 +50,13 @@ proc test_pivotStoreRead*(
         check rc.value.nAccounts == n.uint64
         check rc.value.nSlotLists == n.uint64
         check rc.value.processed == processed
-  for n,w in accKeys:
+        # Stop gossiping (happens whith corrupted database)
+        if rc.value.nAccounts != n.uint64 or
+           rc.value.nSlotLists != n.uint64 or
+           rc.value.processed != processed:
+          return
+  for n in 0 ..< accKeys.len:
+    let w = accKeys[n]
     block:
       let rc = dbBase.recoverPivot(w)
       check rc.isOk

tests/test_sync_snap/test_storage.nim

@@ -12,7 +12,7 @@
 ## Snap sync components tester and TDD environment
 
 import
-  std/[sequtils, strformat, strutils, tables],
+  std/[sequtils, tables],
   eth/[common, p2p],
   unittest2,
   ../../nimbus/db/select_backend,