* Redesign snap1 message GetTrieNodes argument prototypes
why:
A list of sub-objects `seq[SnapTriePath]` is more intuitive to work with
than an opaque definition `seq[seq[Blob]]` because the inner object
`SnapTriePath` object has a dedicated inner structure (for how to
interprete `seq[Blob]`.)
* Collect some public constants into `constants.nim` file
* Reorg `hexary_paths.nim`
why:
+ Collecting nodes following a partial path properly ending at an
extension node failed to collect this last node.
+ Merged the nodes collecting algorithm for persistent and in-memory
into a single generic function `hexary_paths.rootPathExtend()`
info:
Extracted common tasks to `hexary_nodes_helper.nim`
* Implement `StorageRanges` message handler for snap/1 protocol
* Handle last/all node(s) proof conditions at leaf node extractor
detail:
Flag whether the maximum extracted node is the last one in database
No proof needed if the full tree was extracted
* Clean up some helpers & definitions
details:
Move entities to more plausible locations, e.g. `Account` object need
not be dealt with in the range extractor as it applies to any kind of
leaf data.
* Fix next/prev database walk fringe condition
details:
First check needed might be for a leaf node which was done too late.
* Homogenise snap/1 protocol function prototypes
why:
The range arguments `origin` and `limit` data types differed in various
function prototypes (`Hash256` vs. `openArray[byte]`.)
* Implement `GetStorageRange` handler
* Implement server timeout for leaf node retrieval
why:
This feature leaves control on the server for probably costly action
invoked by the network
* Implement maximal reply size for snap service
why:
This feature leaves control on the server for probably costly action
invoked by the network.
* Renaming androgynous sub-object names according to where they belong
why:
These objects are not explicitly dealt with. They give meaning to
some generic wrapper objects. Naming them after their origin may
help troubleshooting.
* Redefine proof nodes list data type for `snap/1` wire protocol
why:
The current specification suffered from the fact that the basic data
type for a proof node is an RLP encoded hexary node. This slightly
confused the encoding/decoding magic.
details:
This is the second attempt, now wrapping the `seq[Blob]` into a
wrapper object of `seq[SnapProof]` for a distinct alias sequence.
In the previous attempt, `SnapProof` was a wrapper object holding the
`Blob` with magic applied to the `seq[]`. This needed the `append`
mixin to strip the outer wrapper that was applied to the `Blob` already
when it was passed as argument.
* Fix some prototype inconsistency
why:
For easy reading, `getAccountRange()` handler return code should
resemble the `accoundRange()` anruments prototype.
* Redefine `seq[Blob]` => `seq[SnapProof]` for `snap/1` protocol
why:
Proof nodes are traded as `Blob` type items rather than Nim objects. So
the RLP transcoder must not extra wrap proofs which are of type
seq[Blob]. Without custom encoding one would produce a
`list(blob(item1), blob(item2) ..)` instead of `list(item1, item2 ..)`.
* Limit leaf extractor by RLP size rather than number of items
why:
To be used serving `snap/1` requests, the result of function
`hexaryRangeLeafsProof()` is limited by the maximal space
needed to serialise the result which will be part of the
`snap/1` repsonse.
* Let the range extractor `hexaryRangeLeafsProof()` return RLP list sizes
why:
When collecting accounts, the size oft the accounts list when encoded
as RLP is continually updated. So the summed up value is available
anyway. For the proof nodes list, there are not many (~ 10) so summing
up is not expensive here.
* Unit tests to verify calculations based on hard coded constants
why:
Sizes of RLP encoded objects are available at run time only.
* Changed argument order for `hexaryRangeLeafsProof()` prototype
why:
Better to read as a stand-alone function (arguments were optimised
for functional pipelines)
* Run sub-range proof tests for extracted ranges