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mirror of https://github.com/postgrespro/pg_probackup.git synced 2025-03-18 21:28:07 +02:00

Skip copy WAL file to archive if already exists

This commit is contained in:
Sergey Cherkashin 2018-10-17 14:44:21 +03:00
parent 8505e78c91
commit 4befefada2

View File

@ -29,6 +29,9 @@ typedef union DataPage
char data[BLCKSZ];
} DataPage;
static bool
fileEqualCRC(const char *path1, const char *path2, bool path2_is_compressed);
#ifdef HAVE_LIBZ
/* Implementation of zlib compression method */
static int32
@ -1092,14 +1095,21 @@ push_wal_file(const char *from_path, const char *to_path, bool is_compress,
FILE *in = NULL;
FILE *out=NULL;
char buf[XLOG_BLCKSZ];
const char *to_path_p = to_path;
const char *to_path_p;
char to_path_temp[MAXPGPATH];
int errno_temp;
#ifdef HAVE_LIBZ
char gz_to_path[MAXPGPATH];
gzFile gz_out = NULL;
if (is_compress)
{
snprintf(gz_to_path, sizeof(gz_to_path), "%s.gz", to_path);
to_path_p = gz_to_path;
}
else
#endif
to_path_p = to_path;
/* open file for read */
in = fopen(from_path, PG_BINARY_R);
@ -1107,30 +1117,30 @@ push_wal_file(const char *from_path, const char *to_path, bool is_compress,
elog(ERROR, "Cannot open source WAL file \"%s\": %s", from_path,
strerror(errno));
/* Check if possible to skip copying */
if (fileExists(to_path_p))
{
if (fileEqualCRC(from_path, to_path_p, is_compress))
return;
/* Do not copy and do not rise error. Just quit as normal. */
else if (!overwrite)
elog(ERROR, "WAL segment \"%s\" already exists.", to_path);
}
/* open backup file for write */
#ifdef HAVE_LIBZ
if (is_compress)
{
snprintf(gz_to_path, sizeof(gz_to_path), "%s.gz", to_path);
if (!overwrite && fileExists(gz_to_path))
elog(ERROR, "WAL segment \"%s\" already exists.", gz_to_path);
snprintf(to_path_temp, sizeof(to_path_temp), "%s.partial", gz_to_path);
gz_out = gzopen(to_path_temp, PG_BINARY_W);
if (gzsetparams(gz_out, compress_level, Z_DEFAULT_STRATEGY) != Z_OK)
elog(ERROR, "Cannot set compression level %d to file \"%s\": %s",
compress_level, to_path_temp, get_gz_error(gz_out, errno));
to_path_p = gz_to_path;
}
else
#endif
{
if (!overwrite && fileExists(to_path))
elog(ERROR, "WAL segment \"%s\" already exists.", to_path);
snprintf(to_path_temp, sizeof(to_path_temp), "%s.partial", to_path);
out = fopen(to_path_temp, PG_BINARY_W);
@ -1724,3 +1734,61 @@ check_file_pages(pgFile *file, XLogRecPtr stop_lsn,
return is_valid;
}
static bool
fileEqualCRC(const char *path1, const char *path2, bool path2_is_compressed)
{
pg_crc32 crc_from;
pg_crc32 crc_to;
/* Get checksum of backup file */
#ifdef HAVE_LIBZ
if (path2_is_compressed)
{
char buf [1024];
gzFile gz_in = NULL;
INIT_CRC32C(crc_to);
gz_in = gzopen(path2, PG_BINARY_R);
if (gz_in == NULL)
{
/* There is no such file or it cannot be read */
elog(LOG,
"Cannot compare WAL file \"%s\" with compressed \"%s\"",
path1, path2);
return false;
}
for (;;)
{
size_t read_len = 0;
read_len = gzread(gz_in, buf, sizeof(buf));
if (read_len != sizeof(buf) && !gzeof(gz_in))
{
/* An error occurred while reading the file */
elog(LOG,
"Cannot compare WAL file \"%s\" with compressed \"%s\"",
path1, path2);
return false;
}
COMP_CRC32C(crc_to, buf, read_len);
if (gzeof(gz_in) || read_len == 0)
break;
}
FIN_CRC32C(crc_to);
if (gzclose(gz_in) != 0)
elog(ERROR, "Cannot close compressed WAL file \"%s\": %s",
path2, get_gz_error(gz_in, errno));
}
else
#endif
{
crc_to = pgFileGetCRC(path2);
}
/* Get checksum of original file */
crc_from = pgFileGetCRC(path1);
return EQ_CRC32C(crc_from, crc_to);
}