On Wed, Nov 03, 2021 at 09:11:24AM +0000, gkokola...@pm.me wrote: > Please find v9 attached.
Thanks. I have looked at 0001 today, and applied it after fixing a
couple of issues. From memory:
- zlib.h was missing from pg_receivewal.c, issue that I noticed after
removing the redefinition of Z_DEFAULT_COMPRESSION because there was
no need for it (did a run with a --without-zlib as well).
- Simplified a bit the error handling for incorrect option
combinations, using a switch/case while on it.
- Renamed the existing variable "compression" in walmethods.c to
compression_level, to reduce any confusion with the introduction of
compression_method. One thing I have noticed is about the tar method,
where we rely on the compression level to decide if compression should
be used or not. There should be some simplifications possible there
but there is a huge take in receivelog.c where we use COMPRESSION_NONE
to track down that we still want to zero a new segment when using tar
method.
- Use of 'I' as short option name, err... After applying the first
batch..
Based on the work of 0001, there were some conflicts with 0002. I
have solved them while reviewing it, and adapted the code to what got
already applied.
+ header_size = LZ4F_compressBegin(ctx, lz4buf, lz4bufsize, NULL);
+ if (LZ4F_isError(header_size))
+ {
+ pg_free(lz4buf);
+ close(fd);
+ return NULL;
+ }
In dir_open_for_write(), I guess that this one is missing one
LZ4F_freeCompressionContext().
+ status = LZ4F_freeDecompressionContext(ctx);
+ if (LZ4F_isError(status))
+ {
+ pg_log_error("could not free LZ4 decompression context: %s",
+ LZ4F_getErrorName(status));
+ exit(1);
+ }
+
+ if (uncompressed_size != WalSegSz)
+ {
+ pg_log_warning("compressed segment file \"%s\" has
incorrect uncompressed size %ld, skipping",
+ dirent->d_name, uncompressed_size);
+ (void) LZ4F_freeDecompressionContext(ctx);
+ continue;
+ }
When the uncompressed size does not match out expected size, the
second LZ4F_freeDecompressionContext() looks unnecessary to me because
we have already one a couple of lines above.
+ ctx_out = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION);
+ lz4bufsize = LZ4F_compressBound(LZ4_IN_SIZE, NULL);
+ if (LZ4F_isError(ctx_out))
+ {
+ close(fd);
+ return NULL;
+ }
LZ4F_compressBound() can be after the check on ctx_out, here.
+ while (1)
+ {
+ char *readp;
+ char *readend;
Simply looping when decompressing a segment to check its size looks
rather unsafe to me. We should leave the loop once uncompressed_size
is strictly more than WalSegSz.
The amount of TAP tests looks fine, and that's consistent with what we
do for zlib^D^D^D^Dgzip. Now, when testing manually pg_receivewal
with various combinations of gzip, lz4 and none, I can see the
following failure in the code that calculates the streaming start
point:
pg_receivewal: error: could not decompress file
"wals//000000010000000000000006.lz4": ERROR_frameType_unknown
In the LZ4 code, this points to lib/lz4frame.c, where we read an
incorrect header (see the part that does not match LZ4F_MAGICNUMBER).
The segments written by pg_receivewal are clean. Please note that
this shows up as well when manually compressing some segments with a
simple lz4 command, to simulate for example the case where a user
compressed some segments by himself/herself before running
pg_receivewal.
So, tour code does LZ4F_createDecompressionContext() followed by a
loop on read() and LZ4F_decompress() that relies on an input and an
output buffer of a fixed 4kB size (we could use 64kB at least here
actually?). So this set of loops looks rather correct to me.
Now, this part is weird:
+ while (readp < readend)
+ {
+ size_t read_size = 1;
+ size_t out_size = 1;
I would have expected read_size to be (readend - readp) to match with
the remaining data in the read buffer that we still need to read.
Shouldn't out_size also be LZ4_CHUNK_SZ to match with the size of the
output buffer where all the contents are read? By setting it to 1, I
think that this is doing more loops into LZ4F_decompress() than really
necessary. It would not hurt either to memset(0) those buffers before
they are used, IMO. I am not completely sure either, but should we
use the number of bytes returned by LZ4F_decompress() as a hint for
the follow-up loops?
Attached is an updated patch, which includes fixes for most of the
issues I am mentioning above. Please note that I have not changed
FindStreamingStart(), so this part is the same as v9.
Thanks,
--
Michael
From 51a2352d2e543795ec201ed444d4e74014c3a2d3 Mon Sep 17 00:00:00 2001
From: Michael Paquier <mich...@paquier.xyz>
Date: Thu, 4 Nov 2021 16:24:48 +0900
Subject: [PATCH v10] Teach pg_receivewal to use LZ4 compression
The program pg_receivewal can use gzip compression to store the received
WAL. This commit teaches it to also be able to use LZ4 compression. It
is required that the binary is build using the -llz4 flag. It is enabled
via the --with-lz4 flag on configuration time.
The option `--compression-method` has been expanded to inlude the value
[LZ4]. The option `--compress` can not be used with LZ4 compression.
Under the hood there is nothing exceptional to be noted. Tar based
archives have not yet been taught to use LZ4 compression. If that is
felt useful, then it is easy to be added in the future.
Tests have been added to verify the creation and correctness of the
generated LZ4 files. The later is achieved by the use of LZ4 program, if
present in the installation.
---
src/bin/pg_basebackup/Makefile | 1 +
src/bin/pg_basebackup/pg_receivewal.c | 144 +++++++++++++++++
src/bin/pg_basebackup/t/020_pg_receivewal.pl | 72 ++++++++-
src/bin/pg_basebackup/walmethods.c | 160 ++++++++++++++++++-
src/bin/pg_basebackup/walmethods.h | 1 +
doc/src/sgml/ref/pg_receivewal.sgml | 8 +-
src/Makefile.global.in | 1 +
7 files changed, 375 insertions(+), 12 deletions(-)
diff --git a/src/bin/pg_basebackup/Makefile b/src/bin/pg_basebackup/Makefile
index 459d514183..fd920fc197 100644
--- a/src/bin/pg_basebackup/Makefile
+++ b/src/bin/pg_basebackup/Makefile
@@ -19,6 +19,7 @@ top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
# make these available to TAP test scripts
+export LZ4
export TAR
# Note that GZIP cannot be used directly as this environment variable is
# used by the command "gzip" to pass down options, so stick with a different
diff --git a/src/bin/pg_basebackup/pg_receivewal.c b/src/bin/pg_basebackup/pg_receivewal.c
index 8acc0fc009..6d090d4c50 100644
--- a/src/bin/pg_basebackup/pg_receivewal.c
+++ b/src/bin/pg_basebackup/pg_receivewal.c
@@ -32,6 +32,10 @@
#include "receivelog.h"
#include "streamutil.h"
+#ifdef HAVE_LIBLZ4
+#include "lz4frame.h"
+#endif
+
/* Time to sleep between reconnection attempts */
#define RECONNECT_SLEEP_TIME 5
@@ -136,6 +140,15 @@ is_xlogfilename(const char *filename, bool *ispartial,
return true;
}
+ /* File looks like a completed LZ4-compressed WAL file */
+ if (fname_len == XLOG_FNAME_LEN + strlen(".lz4") &&
+ strcmp(filename + XLOG_FNAME_LEN, ".lz4") == 0)
+ {
+ *ispartial = false;
+ *wal_compression_method = COMPRESSION_LZ4;
+ return true;
+ }
+
/* File looks like a partial uncompressed WAL file */
if (fname_len == XLOG_FNAME_LEN + strlen(".partial") &&
strcmp(filename + XLOG_FNAME_LEN, ".partial") == 0)
@@ -154,6 +167,15 @@ is_xlogfilename(const char *filename, bool *ispartial,
return true;
}
+ /* File looks like a partial LZ4-compressed WAL file */
+ if (fname_len == XLOG_FNAME_LEN + strlen(".lz4.partial") &&
+ strcmp(filename + XLOG_FNAME_LEN, ".lz4.partial") == 0)
+ {
+ *ispartial = true;
+ *wal_compression_method = COMPRESSION_LZ4;
+ return true;
+ }
+
/* File does not look like something we know */
return false;
}
@@ -284,6 +306,14 @@ FindStreamingStart(uint32 *tli)
* than 4GB, and then compare it to the size of a completed segment.
* The 4 last bytes correspond to the ISIZE member according to
* http://www.zlib.org/rfc-gzip.html.
+ *
+ * For LZ4 compressed segments, uncompress the file in a throw-away
+ * buffer keeping track of the uncompressed size, then compare it to
+ * the size of a completed segment. Per its protocol, LZ4 does not
+ * store the uncompressed size of an object by default. contentSize
+ * is one possible way to do that, but we need to rely on a method
+ * where WAL segments could have been compressed by a different
+ * source than pg_receivewal, like an archive_command.
*/
if (!ispartial && wal_compression_method == COMPRESSION_NONE)
{
@@ -315,6 +345,7 @@ FindStreamingStart(uint32 *tli)
snprintf(fullpath, sizeof(fullpath), "%s/%s", basedir, dirent->d_name);
fd = open(fullpath, O_RDONLY | PG_BINARY, 0);
+
if (fd < 0)
{
pg_log_error("could not open compressed file \"%s\": %m",
@@ -350,6 +381,98 @@ FindStreamingStart(uint32 *tli)
continue;
}
}
+ else if (!ispartial && compression_method == COMPRESSION_LZ4)
+ {
+#ifdef HAVE_LIBLZ4
+#define LZ4_CHUNK_SZ 4096
+ int fd;
+ int r;
+ size_t uncompressed_size = 0;
+ char fullpath[MAXPGPATH * 2];
+ char readbuf[LZ4_CHUNK_SZ];
+ char outbuf[LZ4_CHUNK_SZ];
+ LZ4F_decompressionContext_t ctx = NULL;
+ LZ4F_errorCode_t status;
+
+ snprintf(fullpath, sizeof(fullpath), "%s/%s", basedir, dirent->d_name);
+
+ fd = open(fullpath, O_RDONLY | PG_BINARY, 0);
+ if (fd < 0)
+ {
+ pg_log_error("could not open file \"%s\": %m", fullpath);
+ exit(1);
+ }
+
+ status = LZ4F_createDecompressionContext(&ctx, LZ4F_VERSION);
+ if (LZ4F_isError(status))
+ {
+ pg_log_error("could not create LZ4 decompression context: %s",
+ LZ4F_getErrorName(status));
+ exit(1);
+ }
+
+ while (1)
+ {
+ char *readp;
+ char *readend;
+
+ r = read(fd, readbuf, sizeof(readbuf));
+ if (r < 0)
+ {
+ pg_log_error("could not read file \"%s\": %m", fullpath);
+ exit(1);
+ }
+
+ /* Done reading */
+ if (r == 0)
+ break;
+
+ readp = readbuf;
+ readend = readbuf + r;
+ while (readp < readend)
+ {
+ size_t read_size = 1;
+ size_t out_size = 1;
+
+ status = LZ4F_decompress(ctx, outbuf, &out_size,
+ readbuf, &read_size, NULL);
+ if (LZ4F_isError(status))
+ {
+ pg_log_error("could not decompress file \"%s\": %s",
+ fullpath,
+ LZ4F_getErrorName(status));
+ exit(1);
+ }
+
+ readp += read_size;
+ uncompressed_size += out_size;
+ }
+ }
+
+ close(fd);
+
+ status = LZ4F_freeDecompressionContext(ctx);
+ if (LZ4F_isError(status))
+ {
+ pg_log_error("could not free LZ4 decompression context: %s",
+ LZ4F_getErrorName(status));
+ exit(1);
+ }
+
+ if (uncompressed_size != WalSegSz)
+ {
+ pg_log_warning("compressed segment file \"%s\" has incorrect uncompressed size %ld, skipping",
+ dirent->d_name, uncompressed_size);
+ continue;
+ }
+#else
+ pg_log_error("could not check segment file \"%s\" compressed with LZ4",
+ dirent->d_name);
+ pg_log_error("this build does not support compression with %s",
+ "LZ4");
+ exit(1);
+#endif
+ }
/* Looks like a valid segment. Remember that we saw it. */
if ((segno > high_segno) ||
@@ -650,6 +773,8 @@ main(int argc, char **argv)
case 6:
if (pg_strcasecmp(optarg, "gzip") == 0)
compression_method = COMPRESSION_GZIP;
+ else if (pg_strcasecmp(optarg, "lz4") == 0)
+ compression_method = COMPRESSION_LZ4;
else if (pg_strcasecmp(optarg, "none") == 0)
compression_method = COMPRESSION_NONE;
else
@@ -748,6 +873,25 @@ main(int argc, char **argv)
exit(1);
#endif
break;
+ case COMPRESSION_LZ4:
+#ifdef HAVE_LIBLZ4
+ if (compresslevel != 0)
+ {
+ pg_log_error("cannot use --compress with --compression-method=%s",
+ "lz4");
+ fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
+ progname);
+ exit(1);
+ }
+#else
+ if (compression_method == COMPRESSION_LZ4)
+ {
+ pg_log_error("this build does not support compression with %s",
+ "LZ4");
+ exit(1);
+ }
+ break;
+#endif
}
diff --git a/src/bin/pg_basebackup/t/020_pg_receivewal.pl b/src/bin/pg_basebackup/t/020_pg_receivewal.pl
index 94786f0815..43599d832b 100644
--- a/src/bin/pg_basebackup/t/020_pg_receivewal.pl
+++ b/src/bin/pg_basebackup/t/020_pg_receivewal.pl
@@ -5,7 +5,7 @@ use strict;
use warnings;
use PostgreSQL::Test::Utils;
use PostgreSQL::Test::Cluster;
-use Test::More tests => 37;
+use Test::More tests => 42;
program_help_ok('pg_receivewal');
program_version_ok('pg_receivewal');
@@ -138,13 +138,69 @@ SKIP:
"gzip verified the integrity of compressed WAL segments");
}
+# Check LZ4 compression if available
+SKIP:
+{
+ skip "postgres was not built with LZ4 support", 5
+ if (!check_pg_config("#define HAVE_LIBLZ4 1"));
+
+ # Generate more WAL including one completed, compressed segment.
+ $primary->psql('postgres', 'SELECT pg_switch_wal();');
+ $nextlsn =
+ $primary->safe_psql('postgres', 'SELECT pg_current_wal_insert_lsn();');
+ chomp($nextlsn);
+ $primary->psql('postgres', 'INSERT INTO test_table VALUES (3);');
+
+ # Stream up to the given position.
+ $primary->command_ok(
+ [
+ 'pg_receivewal', '-D',
+ $stream_dir, '--verbose',
+ '--endpos', $nextlsn,
+ '--no-loop', '--compression-method',
+ 'lz4'
+ ],
+ 'streaming some WAL using --compression-method=lz4');
+
+ # Verify that the stored files are generated with their expected
+ # names.
+ my @lz4_wals = glob "$stream_dir/*.lz4";
+ is(scalar(@lz4_wals), 1,
+ "one WAL segment compressed with LZ4 was created");
+ my @lz4_partial_wals = glob "$stream_dir/*.lz4.partial";
+ is(scalar(@lz4_partial_wals),
+ 1, "one partial WAL segment compressed with LZ4 was created");
+
+ # Verify that the start streaming position is computed correctly by
+ # comparing it with the partial file generated previously. The name
+ # of the previous partial, now-completed WAL segment is updated, keeping
+ # its base number.
+ $partial_wals[0] =~ s/(\.gz)?\.partial$/.lz4/;
+ is($lz4_wals[0] eq $partial_wals[0],
+ 1, "one partial WAL segment is now completed");
+ # Update the list of partial wals with the current one.
+ @partial_wals = @lz4_partial_wals;
+
+ # Check the integrity of the completed segment, if LZ4 is an available
+ # command.
+ my $lz4 = $ENV{LZ4};
+ skip "program lz4 is not found in your system", 1
+ if ( !defined $lz4
+ || $lz4 eq ''
+ || system_log($lz4, '--version') != 0);
+
+ my $lz4_is_valid = system_log($lz4, '-t', @lz4_wals);
+ is($lz4_is_valid, 0,
+ "lz4 verified the integrity of compressed WAL segments");
+}
+
# Verify that the start streaming position is computed and that the value is
-# correct regardless of whether ZLIB is available.
+# correct regardless of whether any compression is available.
$primary->psql('postgres', 'SELECT pg_switch_wal();');
$nextlsn =
$primary->safe_psql('postgres', 'SELECT pg_current_wal_insert_lsn();');
chomp($nextlsn);
-$primary->psql('postgres', 'INSERT INTO test_table VALUES (3);');
+$primary->psql('postgres', 'INSERT INTO test_table VALUES (4);');
$primary->command_ok(
[
'pg_receivewal', '-D', $stream_dir, '--verbose',
@@ -152,7 +208,7 @@ $primary->command_ok(
],
"streaming some WAL");
-$partial_wals[0] =~ s/(\.gz)?.partial//;
+$partial_wals[0] =~ s/(\.gz|\.lz4)?.partial//;
ok(-e $partial_wals[0], "check that previously partial WAL is now complete");
# Permissions on WAL files should be default
@@ -190,7 +246,7 @@ my $walfile_streamed = $primary->safe_psql(
# Switch to a new segment, to make sure that the segment retained by the
# slot is still streamed. This may not be necessary, but play it safe.
-$primary->psql('postgres', 'INSERT INTO test_table VALUES (4);');
+$primary->psql('postgres', 'INSERT INTO test_table VALUES (5);');
$primary->psql('postgres', 'SELECT pg_switch_wal();');
$nextlsn =
$primary->safe_psql('postgres', 'SELECT pg_current_wal_insert_lsn();');
@@ -198,7 +254,7 @@ chomp($nextlsn);
# Add a bit more data to accelerate the end of the next pg_receivewal
# commands.
-$primary->psql('postgres', 'INSERT INTO test_table VALUES (5);');
+$primary->psql('postgres', 'INSERT INTO test_table VALUES (6);');
# Check case where the slot does not exist.
$primary->command_fails_like(
@@ -253,13 +309,13 @@ $standby->promote;
# on the new timeline.
my $walfile_after_promotion = $standby->safe_psql('postgres',
"SELECT pg_walfile_name(pg_current_wal_insert_lsn());");
-$standby->psql('postgres', 'INSERT INTO test_table VALUES (6);');
+$standby->psql('postgres', 'INSERT INTO test_table VALUES (7);');
$standby->psql('postgres', 'SELECT pg_switch_wal();');
$nextlsn =
$standby->safe_psql('postgres', 'SELECT pg_current_wal_insert_lsn();');
chomp($nextlsn);
# This speeds up the operation.
-$standby->psql('postgres', 'INSERT INTO test_table VALUES (7);');
+$standby->psql('postgres', 'INSERT INTO test_table VALUES (8);');
# Now try to resume from the slot after the promotion.
my $timeline_dir = $primary->basedir . '/timeline_wal';
diff --git a/src/bin/pg_basebackup/walmethods.c b/src/bin/pg_basebackup/walmethods.c
index 52f314af3b..f1ba2a828a 100644
--- a/src/bin/pg_basebackup/walmethods.c
+++ b/src/bin/pg_basebackup/walmethods.c
@@ -17,6 +17,10 @@
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>
+
+#ifdef HAVE_LIBLZ4
+#include <lz4frame.h>
+#endif
#ifdef HAVE_LIBZ
#include <zlib.h>
#endif
@@ -30,6 +34,9 @@
/* Size of zlib buffer for .tar.gz */
#define ZLIB_OUT_SIZE 4096
+/* Size of LZ4 input chunk for .lz4 */
+#define LZ4_IN_SIZE 4096
+
/*-------------------------------------------------------------------------
* WalDirectoryMethod - write wal to a directory looking like pg_wal
*-------------------------------------------------------------------------
@@ -60,6 +67,11 @@ typedef struct DirectoryMethodFile
#ifdef HAVE_LIBZ
gzFile gzfp;
#endif
+#ifdef HAVE_LIBLZ4
+ LZ4F_compressionContext_t ctx;
+ size_t lz4bufsize;
+ void *lz4buf;
+#endif
} DirectoryMethodFile;
static const char *
@@ -76,7 +88,8 @@ dir_get_file_name(const char *pathname, const char *temp_suffix)
snprintf(filename, MAXPGPATH, "%s%s%s",
pathname,
- dir_data->compression_method == COMPRESSION_GZIP ? ".gz" : "",
+ dir_data->compression_method == COMPRESSION_GZIP ? ".gz" :
+ dir_data->compression_method == COMPRESSION_LZ4 ? ".lz4" : "",
temp_suffix ? temp_suffix : "");
return filename;
@@ -92,6 +105,11 @@ dir_open_for_write(const char *pathname, const char *temp_suffix, size_t pad_to_
#ifdef HAVE_LIBZ
gzFile gzfp = NULL;
#endif
+#ifdef HAVE_LIBLZ4
+ LZ4F_compressionContext_t ctx = NULL;
+ size_t lz4bufsize = 0;
+ void *lz4buf = NULL;
+#endif
filename = dir_get_file_name(pathname, temp_suffix);
snprintf(tmppath, sizeof(tmppath), "%s/%s",
@@ -126,6 +144,50 @@ dir_open_for_write(const char *pathname, const char *temp_suffix, size_t pad_to_
}
}
#endif
+#ifdef HAVE_LIBLZ4
+ if (dir_data->compression_method == COMPRESSION_LZ4)
+ {
+ size_t ctx_out;
+ size_t header_size;
+
+ ctx_out = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION);
+ if (LZ4F_isError(ctx_out))
+ {
+ close(fd);
+ return NULL;
+ }
+
+ lz4bufsize = LZ4F_compressBound(LZ4_IN_SIZE, NULL);
+ lz4buf = pg_malloc0(lz4bufsize);
+
+ /* add the header */
+ header_size = LZ4F_compressBegin(ctx, lz4buf, lz4bufsize, NULL);
+ if (LZ4F_isError(header_size))
+ {
+ (void) LZ4F_freeCompressionContext(ctx);
+ pg_free(lz4buf);
+ close(fd);
+ return NULL;
+ }
+
+ errno = 0;
+ if (write(fd, lz4buf, header_size) != header_size)
+ {
+ int save_errno = errno;
+
+ (void) LZ4F_compressEnd(ctx, lz4buf, lz4bufsize, NULL);
+ (void) LZ4F_freeCompressionContext(ctx);
+ pg_free(lz4buf);
+ close(fd);
+
+ /*
+ * If write didn't set errno, assume problem is no disk space.
+ */
+ errno = save_errno ? save_errno : ENOSPC;
+ return NULL;
+ }
+ }
+#endif
/* Do pre-padding on non-compressed files */
if (pad_to_size && dir_data->compression_method == COMPRESSION_NONE)
@@ -176,6 +238,16 @@ dir_open_for_write(const char *pathname, const char *temp_suffix, size_t pad_to_
if (dir_data->compression_method == COMPRESSION_GZIP)
gzclose(gzfp);
else
+#endif
+#ifdef HAVE_LIBLZ4
+ if (dir_data->compression_method == COMPRESSION_LZ4)
+ {
+ (void) LZ4F_compressEnd(ctx, lz4buf, lz4bufsize, NULL);
+ (void) LZ4F_freeCompressionContext(ctx);
+ pg_free(lz4buf);
+ close(fd);
+ }
+ else
#endif
close(fd);
return NULL;
@@ -187,6 +259,15 @@ dir_open_for_write(const char *pathname, const char *temp_suffix, size_t pad_to_
if (dir_data->compression_method == COMPRESSION_GZIP)
f->gzfp = gzfp;
#endif
+#ifdef HAVE_LIBLZ4
+ if (dir_data->compression_method == COMPRESSION_LZ4)
+ {
+ f->ctx = ctx;
+ f->lz4buf = lz4buf;
+ f->lz4bufsize = lz4bufsize;
+ }
+#endif
+
f->fd = fd;
f->currpos = 0;
f->pathname = pg_strdup(pathname);
@@ -209,6 +290,43 @@ dir_write(Walfile f, const void *buf, size_t count)
if (dir_data->compression_method == COMPRESSION_GZIP)
r = (ssize_t) gzwrite(df->gzfp, buf, count);
else
+#endif
+#ifdef HAVE_LIBLZ4
+ if (dir_data->compression_method == COMPRESSION_LZ4)
+ {
+ size_t chunk;
+ size_t remaining;
+ const void *inbuf = buf;
+
+ remaining = count;
+ while (remaining > 0)
+ {
+ size_t compressed;
+
+ if (remaining > LZ4_IN_SIZE)
+ chunk = LZ4_IN_SIZE;
+ else
+ chunk = remaining;
+
+ remaining -= chunk;
+ compressed = LZ4F_compressUpdate(df->ctx,
+ df->lz4buf, df->lz4bufsize,
+ inbuf, chunk,
+ NULL);
+
+ if (LZ4F_isError(compressed))
+ return -1;
+
+ if (write(df->fd, df->lz4buf, compressed) != compressed)
+ return -1;
+
+ inbuf = ((char *) inbuf) + chunk;
+ }
+
+ /* Our caller keeps track of the uncompressed size. */
+ r = (ssize_t) count;
+ }
+ else
#endif
r = write(df->fd, buf, count);
if (r > 0)
@@ -239,6 +357,25 @@ dir_close(Walfile f, WalCloseMethod method)
if (dir_data->compression_method == COMPRESSION_GZIP)
r = gzclose(df->gzfp);
else
+#endif
+#ifdef HAVE_LIBLZ4
+ if (dir_data->compression_method == COMPRESSION_LZ4)
+ {
+ size_t compressed;
+
+ compressed = LZ4F_compressEnd(df->ctx,
+ df->lz4buf, df->lz4bufsize,
+ NULL);
+
+ if (LZ4F_isError(compressed))
+ return -1;
+
+ if (write(df->fd, df->lz4buf, compressed) != compressed)
+ return -1;
+
+ r = close(df->fd);
+ }
+ else
#endif
r = close(df->fd);
@@ -293,6 +430,12 @@ dir_close(Walfile f, WalCloseMethod method)
}
}
+#ifdef HAVE_LIBLZ4
+ pg_free(df->lz4buf);
+ /* supports free on NULL */
+ LZ4F_freeCompressionContext(df->ctx);
+#endif
+
pg_free(df->pathname);
pg_free(df->fullpath);
if (df->temp_suffix)
@@ -317,6 +460,21 @@ dir_sync(Walfile f)
return -1;
}
#endif
+#ifdef HAVE_LIBLZ4
+ if (dir_data->compression_method == COMPRESSION_LZ4)
+ {
+ DirectoryMethodFile *df = (DirectoryMethodFile *) f;
+ size_t compressed;
+
+ /* Flush any internal buffers */
+ compressed = LZ4F_flush(df->ctx, df->lz4buf, df->lz4bufsize, NULL);
+ if (LZ4F_isError(compressed))
+ return -1;
+
+ if (write(df->fd, df->lz4buf, compressed) != compressed)
+ return -1;
+ }
+#endif
return fsync(((DirectoryMethodFile *) f)->fd);
}
diff --git a/src/bin/pg_basebackup/walmethods.h b/src/bin/pg_basebackup/walmethods.h
index 5dfe330ea5..f9b6a1646a 100644
--- a/src/bin/pg_basebackup/walmethods.h
+++ b/src/bin/pg_basebackup/walmethods.h
@@ -22,6 +22,7 @@ typedef enum
/* Types of compression supported */
typedef enum
{
+ COMPRESSION_LZ4,
COMPRESSION_GZIP,
COMPRESSION_NONE
} WalCompressionMethod;
diff --git a/doc/src/sgml/ref/pg_receivewal.sgml b/doc/src/sgml/ref/pg_receivewal.sgml
index 79a4436ab9..5147928cce 100644
--- a/doc/src/sgml/ref/pg_receivewal.sgml
+++ b/doc/src/sgml/ref/pg_receivewal.sgml
@@ -268,13 +268,15 @@ PostgreSQL documentation
<listitem>
<para>
Enables compression of write-ahead logs using the specified method.
- Supported values <literal>gzip</literal>, and
- <literal>none</literal>.
+ Supported values <literal>gzip</literal>, <literal>lz4</literal>
+ (if <productname>PostgreSQL</productname> was compiled with
+ <option>--with-lz4</option>) and <literal>none</literal>.
</para>
<para>
The suffix <filename>.gz</filename> will automatically be added to
- all filenames when using <literal>gzip</literal>
+ all filenames when using <literal>gzip</literal>, and the suffix
+ <filename>.lz4</filename> is added when using <literal>lz4</literal>.
</para>
</listitem>
</varlistentry>
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 533c12fef9..05c54b27de 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -350,6 +350,7 @@ XGETTEXT = @XGETTEXT@
GZIP = gzip
BZIP2 = bzip2
+LZ4 = lz4
DOWNLOAD = wget -O $@ --no-use-server-timestamps
#DOWNLOAD = curl -o $@
--
2.33.1
signature.asc
Description: PGP signature
