xxq250
/
homework-jianmu
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

enh: scan forward step by step in walScanLogGetLastVer

This commit is contained in:
benguang.zhao 2022-11-01 15:25:18 +08:00
parent 07db554fab
commit 6907e3dfe3
1 changed files with 16 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
source/libs/wal/src/walMeta.c
View File

@ -65,6 +65,7 @@ static FORCE_INLINE int64_t walScanLogGetLastVer(SWal* pWal, int32_t fileIdx) {
// ensure size as non-negative
pFileInfo->fileSize = TMAX(0, pFileInfo->fileSize);
int64_t stepSize = WAL_SCAN_BUF_SIZE;
uint64_t magic = WAL_MAGIC;
int64_t walCkHeadSz = sizeof(SWalCkHead);
int64_t end = fileSize;
@ -74,23 +75,25 @@ static FORCE_INLINE int64_t walScanLogGetLastVer(SWal* pWal, int32_t fileIdx) {
char* buf = NULL;
int64_t found = -1;
bool firstTrial = pFileInfo->fileSize < fileSize;
int64_t border = TMIN(pFileInfo->fileSize, fileSize);
int64_t offsetForward = border - stepSize + walCkHeadSz - 1;
int64_t offsetBackward = border;
// search for the valid last WAL entry, e.g. block by block
while (1) {
offset = (firstTrial) ? pFileInfo->fileSize : TMAX(0, end - WAL_SCAN_BUF_SIZE);
offset = (firstTrial) ? TMIN(fileSize, offsetForward + stepSize - walCkHeadSz + 1)
: TMAX(0, offsetBackward - stepSize + walCkHeadSz - 1);
end = TMIN(offset + stepSize, fileSize);
if (firstTrial) {
offsetForward = offset;
} else {
offsetBackward = offset;
}
ASSERT(offset <= end);
readSize = end - offset;
capacity = readSize + sizeof(magic);
int64_t limit = WAL_RECOV_SIZE_LIMIT;
if (limit < readSize) {
wError("vgId:%d, possibly corrupted WAL range exceeds size limit (i.e. %" PRId64 " bytes). offset:%" PRId64
", end:%" PRId64 ", file:%s",
pWal->cfg.vgId, limit, offset, end, fnameStr);
terrno = TSDB_CODE_WAL_SIZE_LIMIT;
goto _err;
}
void* ptr = taosMemoryRealloc(buf, capacity);
if (ptr == NULL) {
terrno = TSDB_CODE_WAL_OUT_OF_MEMORY;
@ -127,6 +130,7 @@ static FORCE_INLINE int64_t walScanLogGetLastVer(SWal* pWal, int32_t fileIdx) {
}
logContent = (SWalCkHead*)(buf + pos);
if (walValidHeadCksum(logContent) != 0) {
terrno = TSDB_CODE_WAL_CHKSUM_MISMATCH;
wWarn("vgId:%d, failed to validate checksum of wal entry header. offset:%" PRId64 ", file:%s", pWal->cfg.vgId,
offset + pos, fnameStr);
haystack = buf + pos + 1;
@ -183,11 +187,9 @@ static FORCE_INLINE int64_t walScanLogGetLastVer(SWal* pWal, int32_t fileIdx) {
haystack = buf + pos + 1;
}
if (end == fileSize) firstTrial = false;
if (firstTrial && terrno == TSDB_CODE_SUCCESS) continue;
if (found >= 0 || offset == 0) break;
// go backwards, e.g. by at most one WAL scan buf size
end = TMIN(offset + walCkHeadSz - 1, fileSize);
firstTrial = false;
}
// determine end of last entry