era: speed up index reading (#2202)

This commit is contained in:
Jacek Sieka 2024-05-22 09:27:23 +02:00 committed by GitHub
parent e566e89d03
commit 308bd51bbd
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 18 additions and 17 deletions

View File

@ -99,30 +99,35 @@ proc appendRecord(f: IoHandle, index: BlockIndex): Result[int64, string] =
f.appendIndex(index.startNumber, index.offsets)
proc readBlockIndex*(f: IoHandle): Result[BlockIndex, string] =
var
buf: seq[byte]
pos: int
let
startPos = ?f.getFilePos().mapErr(toString)
fileSize = ?f.getFileSize().mapErr(toString)
header = ?f.readHeader()
header = ?f.readRecord(buf)
if header.typ != E2BlockIndex:
return err("not an index")
if header.len < 16:
if buf.len < 16:
return err("index entry too small")
if header.len mod 8 != 0:
if buf.len mod 8 != 0:
return err("index length invalid")
var buf: array[8, byte]
?f.readFileExact(buf)
let
blockNumber = uint64.fromBytesLE(buf)
count = header.len div 8 - 2
blockNumber = uint64.fromBytesLE(buf.toOpenArray(pos, pos + 7))
count = buf.len div 8 - 2
pos += 8
# technically not an error, but we'll throw this sanity check in here..
if blockNumber > int32.high().uint64:
return err("fishy block number")
var offsets = newSeqUninitialized[int64](count)
for i in 0 ..< count:
?f.readFileExact(buf)
let
offset = uint64.fromBytesLE(buf)
offset = uint64.fromBytesLE(buf.toOpenArray(pos, pos + 7))
absolute =
if offset == 0:
0'i64
@ -131,17 +136,13 @@ proc readBlockIndex*(f: IoHandle): Result[BlockIndex, string] =
cast[int64](cast[uint64](startPos) + offset)
if absolute < 0 or absolute > fileSize:
return err("Invalid offset")
return err("invalid offset")
offsets[i] = absolute
pos += 8
?f.readFileExact(buf)
if uint64(count) != uint64.fromBytesLE(buf):
if uint64(count) != uint64.fromBytesLE(buf.toOpenArray(pos, pos + 7)):
return err("invalid count")
# technically not an error, but we'll throw this sanity check in here..
if blockNumber > int32.high().uint64:
return err("fishy block number")
ok(BlockIndex(startNumber: blockNumber, offsets: offsets))
proc skipRecord*(f: IoHandle): Result[void, string] =