#include "access/tuptoaster.h"
#include "access/xact.h"
#include "catalog/catalog.h"
+#include "common/pg_lzcompress.h"
#include "miscadmin.h"
#include "utils/fmgroids.h"
-#include "utils/pg_lzcompress.h"
#include "utils/rel.h"
#include "utils/typcache.h"
#include "utils/tqual.h"
#undef TOAST_DEBUG
+/*
+ * The information at the start of the compressed toast data.
+ */
+typedef struct toast_compress_header
+{
+ int32 vl_len_; /* varlena header (do not touch directly!) */
+ int32 rawsize;
+} toast_compress_header;
+
+/*
+ * Utilities for manipulation of header information for compressed
+ * toast entries.
+ */
+#define TOAST_COMPRESS_HDRSZ ((int32) sizeof(toast_compress_header))
+#define TOAST_COMPRESS_RAWSIZE(ptr) (((toast_compress_header *) ptr)->rawsize)
+#define TOAST_COMPRESS_RAWDATA(ptr) \
+ (((char *) ptr) + TOAST_COMPRESS_HDRSZ)
+#define TOAST_COMPRESS_SET_RAWSIZE(ptr, len) \
+ (((toast_compress_header *) ptr)->rawsize = len)
+
static void toast_delete_datum(Relation rel, Datum value);
static Datum toast_save_datum(Relation rel, Datum value,
struct varlena * oldexternal, int options);
static struct varlena *toast_fetch_datum(struct varlena * attr);
static struct varlena *toast_fetch_datum_slice(struct varlena * attr,
int32 sliceoffset, int32 length);
+static struct varlena *toast_decompress_datum(struct varlena * attr);
static int toast_open_indexes(Relation toastrel,
LOCKMODE lock,
Relation **toastidxs,
/* If it's compressed, decompress it */
if (VARATT_IS_COMPRESSED(attr))
{
- PGLZ_Header *tmp = (PGLZ_Header *) attr;
-
- attr = (struct varlena *) palloc(PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
- SET_VARSIZE(attr, PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
- pglz_decompress(tmp, VARDATA(attr));
+ struct varlena *tmp = attr;
+ attr = toast_decompress_datum(tmp);
pfree(tmp);
}
}
/*
* This is a compressed value inside of the main tuple
*/
- PGLZ_Header *tmp = (PGLZ_Header *) attr;
-
- attr = (struct varlena *) palloc(PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
- SET_VARSIZE(attr, PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
- pglz_decompress(tmp, VARDATA(attr));
+ attr = toast_decompress_datum(attr);
}
else if (VARATT_IS_SHORT(attr))
{
if (VARATT_IS_COMPRESSED(preslice))
{
- PGLZ_Header *tmp = (PGLZ_Header *) preslice;
- Size size = PGLZ_RAW_SIZE(tmp) + VARHDRSZ;
-
- preslice = (struct varlena *) palloc(size);
- SET_VARSIZE(preslice, size);
- pglz_decompress(tmp, VARDATA(preslice));
+ struct varlena *tmp = preslice;
+ preslice = toast_decompress_datum(tmp);
- if (tmp != (PGLZ_Header *) attr)
+ if (tmp != attr)
pfree(tmp);
}
{
struct varlena *tmp;
int32 valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
+ int32 len;
Assert(!VARATT_IS_EXTERNAL(DatumGetPointer(value)));
Assert(!VARATT_IS_COMPRESSED(DatumGetPointer(value)));
valsize > PGLZ_strategy_default->max_input_size)
return PointerGetDatum(NULL);
- tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize));
+ tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize) +
+ TOAST_COMPRESS_HDRSZ);
/*
* We recheck the actual size even if pglz_compress() reports success,
* only one header byte and no padding if the value is short enough. So
* we insist on a savings of more than 2 bytes to ensure we have a gain.
*/
- if (pglz_compress(VARDATA_ANY(DatumGetPointer(value)), valsize,
- (PGLZ_Header *) tmp, PGLZ_strategy_default) &&
- VARSIZE(tmp) < valsize - 2)
+ len = pglz_compress(VARDATA_ANY(DatumGetPointer(value)),
+ valsize,
+ TOAST_COMPRESS_RAWDATA(tmp),
+ PGLZ_strategy_default);
+ if (len >= 0 &&
+ len + TOAST_COMPRESS_HDRSZ < valsize - 2)
{
+ TOAST_COMPRESS_SET_RAWSIZE(tmp, valsize);
+ SET_VARSIZE_COMPRESSED(tmp, len + TOAST_COMPRESS_HDRSZ);
/* successful compression */
return PointerGetDatum(tmp);
}
return result;
}
+/* ----------
+ * toast_decompress_datum -
+ *
+ * Decompress a compressed version of a varlena datum
+ */
+static struct varlena *
+toast_decompress_datum(struct varlena * attr)
+{
+ struct varlena *result;
+
+ Assert(VARATT_IS_COMPRESSED(attr));
+
+ result = (struct varlena *)
+ palloc(TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
+ SET_VARSIZE(result, TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
+
+ if (pglz_decompress(TOAST_COMPRESS_RAWDATA(attr),
+ VARSIZE(attr) - TOAST_COMPRESS_HDRSZ,
+ VARDATA(result),
+ TOAST_COMPRESS_RAWSIZE(attr)) < 0)
+ elog(ERROR, "compressed data is corrupted");
+
+ return result;
+}
+
+
/* ----------
* toast_open_indexes
*
jsonfuncs.o like.o lockfuncs.o mac.o misc.o nabstime.o name.o \
network.o network_gist.o network_selfuncs.o \
numeric.o numutils.o oid.o oracle_compat.o \
- orderedsetaggs.o pg_lzcompress.o pg_locale.o pg_lsn.o \
- pgstatfuncs.o pseudotypes.o quote.o rangetypes.o rangetypes_gist.o \
+ orderedsetaggs.o pg_locale.o pg_lsn.o pgstatfuncs.o \
+ pseudotypes.o quote.o rangetypes.o rangetypes_gist.o \
rangetypes_selfuncs.o rangetypes_spgist.o rangetypes_typanalyze.o \
regexp.o regproc.o ri_triggers.o rowtypes.o ruleutils.o \
selfuncs.o tid.o timestamp.o trigfuncs.o \
override CPPFLAGS := -DFRONTEND $(CPPFLAGS)
LIBS += $(PTHREAD_LIBS)
-OBJS_COMMON = exec.o pgfnames.o psprintf.o relpath.o rmtree.o string.o username.o wait_error.o
+OBJS_COMMON = exec.o pg_lzcompress.o pgfnames.o psprintf.o relpath.o \
+ rmtree.o string.o username.o wait_error.o
OBJS_FRONTEND = $(OBJS_COMMON) fe_memutils.o
*
* Entry routines:
*
- * bool
- * pglz_compress(const char *source, int32 slen, PGLZ_Header *dest,
+ * int32
+ * pglz_compress(const char *source, int32 slen, char *dest,
* const PGLZ_Strategy *strategy);
*
* source is the input data to be compressed.
* the compression algorithm. If NULL, the compiled
* in default strategy is used.
*
- * The return value is TRUE if compression succeeded,
- * FALSE if not; in the latter case the contents of dest
- * are undefined.
+ * The return value is the number of bytes written in the
+ * buffer dest, or -1 if compression fails; in the latter
+ * case the contents of dest are undefined.
*
- * void
- * pglz_decompress(const PGLZ_Header *source, char *dest)
+ * int32
+ * pglz_decompress(const char *source, int32 slen, char *dest,
+ * int32 rawsize)
*
* source is the compressed input.
*
+ * slen is the length of the compressed input.
+ *
* dest is the area where the uncompressed data will be
* written to. It is the callers responsibility to
- * provide enough space. The required amount can be
- * obtained with the macro PGLZ_RAW_SIZE(source).
+ * provide enough space.
*
* The data is written to buff exactly as it was handed
* to pglz_compress(). No terminating zero byte is added.
*
- * The decompression algorithm and internal data format:
+ * rawsize is the length of the uncompressed data.
*
- * PGLZ_Header is defined as
+ * The return value is the number of bytes written in the
+ * buffer dest, or -1 if decompression fails.
*
- * typedef struct PGLZ_Header {
- * int32 vl_len_;
- * int32 rawsize;
- * }
+ * The decompression algorithm and internal data format:
*
- * The header is followed by the compressed data itself.
+ * It is made with the compressed data itself.
*
* The data representation is easiest explained by describing
* the process of decompression.
*
- * If VARSIZE(x) == rawsize + sizeof(PGLZ_Header), then the data
+ * If compressed_size == rawsize, then the data
* is stored uncompressed as plain bytes. Thus, the decompressor
- * simply copies rawsize bytes from the location after the
- * header to the destination.
+ * simply copies rawsize bytes to the destination.
*
- * Otherwise the first byte after the header tells what to do
- * the next 8 times. We call this the control byte.
+ * Otherwise the first byte tells what to do the next 8 times.
+ * We call this the control byte.
*
* An unset bit in the control byte means, that one uncompressed
* byte follows, which is copied from input to output.
*
* Copyright (c) 1999-2015, PostgreSQL Global Development Group
*
- * src/backend/utils/adt/pg_lzcompress.c
+ * src/common/pg_lzcompress.c
* ----------
*/
+#ifndef FRONTEND
#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
#include <limits.h>
-#include "utils/pg_lzcompress.h"
+#include "common/pg_lzcompress.h"
/* ----------
/* ----------
* pglz_compress -
*
- * Compresses source into dest using strategy.
+ * Compresses source into dest using strategy. Returns the number of
+ * bytes written in buffer dest, or -1 if compression fails.
* ----------
*/
-bool
-pglz_compress(const char *source, int32 slen, PGLZ_Header *dest,
+int32
+pglz_compress(const char *source, int32 slen, char *dest,
const PGLZ_Strategy *strategy)
{
- unsigned char *bp = ((unsigned char *) dest) + sizeof(PGLZ_Header);
+ unsigned char *bp = (unsigned char *) dest;
unsigned char *bstart = bp;
int hist_next = 1;
bool hist_recycle = false;
if (strategy->match_size_good <= 0 ||
slen < strategy->min_input_size ||
slen > strategy->max_input_size)
- return false;
-
- /*
- * Save the original source size in the header.
- */
- dest->rawsize = slen;
+ return -1;
/*
* Limit the match parameters to the supported range.
* allow 4 slop bytes.
*/
if (bp - bstart >= result_max)
- return false;
+ return -1;
/*
* If we've emitted more than first_success_by bytes without finding
* pre-compressed data).
*/
if (!found_match && bp - bstart >= strategy->first_success_by)
- return false;
+ return -1;
/*
* Try to find a match in the history
*ctrlp = ctrlb;
result_size = bp - bstart;
if (result_size >= result_max)
- return false;
-
- /*
- * Success - need only fill in the actual length of the compressed datum.
- */
- SET_VARSIZE_COMPRESSED(dest, result_size + sizeof(PGLZ_Header));
+ return -1;
- return true;
+ /* success */
+ return result_size;
}
/* ----------
* pglz_decompress -
*
- * Decompresses source into dest.
+ * Decompresses source into dest. Returns the number of bytes
+ * decompressed in the destination buffer, or -1 if decompression
+ * fails.
* ----------
*/
-void
-pglz_decompress(const PGLZ_Header *source, char *dest)
+int32
+pglz_decompress(const char *source, int32 slen, char *dest,
+ int32 rawsize)
{
const unsigned char *sp;
const unsigned char *srcend;
unsigned char *dp;
unsigned char *destend;
- sp = ((const unsigned char *) source) + sizeof(PGLZ_Header);
- srcend = ((const unsigned char *) source) + VARSIZE(source);
+ sp = (const unsigned char *) source;
+ srcend = ((const unsigned char *) source) + slen;
dp = (unsigned char *) dest;
- destend = dp + source->rawsize;
+ destend = dp + rawsize;
while (sp < srcend && dp < destend)
{
* Check we decompressed the right amount.
*/
if (dp != destend || sp != srcend)
- elog(ERROR, "compressed data is corrupt");
+ return -1;
/*
* That's it.
*/
+ return rawsize;
}
*
* Definitions for the builtin LZ compressor
*
- * src/include/utils/pg_lzcompress.h
+ * src/include/common/pg_lzcompress.h
* ----------
*/
#define _PG_LZCOMPRESS_H_
-/* ----------
- * PGLZ_Header -
- *
- * The information at the start of the compressed data.
- * ----------
- */
-typedef struct PGLZ_Header
-{
- int32 vl_len_; /* varlena header (do not touch directly!) */
- int32 rawsize;
-} PGLZ_Header;
-
-
/* ----------
* PGLZ_MAX_OUTPUT -
*
* We allow 4 bytes for overrun before detecting compression failure.
* ----------
*/
-#define PGLZ_MAX_OUTPUT(_dlen) ((_dlen) + 4 + sizeof(PGLZ_Header))
-
-/* ----------
- * PGLZ_RAW_SIZE -
- *
- * Macro to determine the uncompressed data size contained
- * in the entry.
- * ----------
- */
-#define PGLZ_RAW_SIZE(_lzdata) ((_lzdata)->rawsize)
+#define PGLZ_MAX_OUTPUT(_dlen) ((_dlen) + 4)
/* ----------
* Global function declarations
* ----------
*/
-extern bool pglz_compress(const char *source, int32 slen, PGLZ_Header *dest,
+extern int32 pglz_compress(const char *source, int32 slen, char *dest,
const PGLZ_Strategy *strategy);
-extern void pglz_decompress(const PGLZ_Header *source, char *dest);
+extern int32 pglz_decompress(const char *source, int32 slen, char *dest,
+ int32 rawsize);
#endif /* _PG_LZCOMPRESS_H_ */
push(@pgportfiles, 'rint.c') if ($vsVersion < '12.00');
our @pgcommonallfiles = qw(
- exec.c pgfnames.c psprintf.c relpath.c rmtree.c string.c username.c wait_error.c);
+ exec.c pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
+ string.c username.c wait_error.c);
our @pgcommonfrontendfiles = (@pgcommonallfiles, qw(fe_memutils.c));
PGEventResultDestroy
PGFInfoFunction
PGFunction
-PGLZ_Header
PGLZ_HistEntry
PGLZ_Strategy
PGMessageField
projects / postgresql / commitdiff