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Add pglz compression method
Signed-off-by: Ildus Kurbangaliev <i.kurbangaliev@gmail.com>
1 parent b2539d7 commit d7c018d

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+178
-3
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6 files changed

+178
-3
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‎src/backend/access/compression/Makefile

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -12,6 +12,6 @@ subdir = src/backend/access/compression
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top_builddir = ../../../..
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include $(top_builddir)/src/Makefile.global
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15-
OBJS = cmapi.o
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OBJS = cm_pglz.o cmapi.o
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include $(top_srcdir)/src/backend/common.mk

‎src/backend/access/compression/cm_pglz.c

Lines changed: 166 additions & 0 deletions
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@@ -0,0 +1,166 @@
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/*-------------------------------------------------------------------------
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*
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* cm_pglz.c
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* pglz compression method
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*
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* Copyright (c) 2015-2018, PostgreSQL Global Development Group
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*
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*
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* IDENTIFICATION
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* src/backend/access/compression/cm_pglz.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/cmapi.h"
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#include "commands/defrem.h"
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#include "common/pg_lzcompress.h"
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#include "nodes/parsenodes.h"
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#include "utils/builtins.h"
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#define PGLZ_OPTIONS_COUNT 6
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static char *PGLZ_options[PGLZ_OPTIONS_COUNT] = {
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"min_input_size",
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"max_input_size",
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"min_comp_rate",
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"first_success_by",
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"match_size_good",
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"match_size_drop"
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};
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/*
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* Convert value from reloptions to int32, and report if it is not correct.
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* Also checks parameter names
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*/
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static int32
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parse_option(char *name, char *value)
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{
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int i;
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for (i = 0; i < PGLZ_OPTIONS_COUNT; i++)
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{
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if (strcmp(PGLZ_options[i], name) == 0)
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return pg_atoi(value, 4, 0);
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}
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_PARAMETER),
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errmsg("unexpected parameter for pglz: \"%s\"", name)));
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}
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/*
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* Check PGLZ options if specified
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*/
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static void
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pglz_cmcheck(Form_pg_attribute att, List *options)
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{
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ListCell *lc;
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foreach(lc, options)
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{
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DefElem *def = (DefElem *) lfirst(lc);
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parse_option(def->defname, defGetString(def));
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}
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}
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/*
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* Configure PGLZ_Strategy struct for compression function
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*/
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static void *
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pglz_cminitstate(Oid acoid, List *options)
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{
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ListCell *lc;
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PGLZ_Strategy *strategy = palloc(sizeof(PGLZ_Strategy));
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/* initialize with default strategy values */
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memcpy(strategy, PGLZ_strategy_default, sizeof(PGLZ_Strategy));
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foreach(lc, options)
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{
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DefElem *def = (DefElem *) lfirst(lc);
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int32 val = parse_option(def->defname, defGetString(def));
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/* fill the strategy */
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if (strcmp(def->defname, "min_input_size") == 0)
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strategy->min_input_size = val;
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else if (strcmp(def->defname, "max_input_size") == 0)
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strategy->max_input_size = val;
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else if (strcmp(def->defname, "min_comp_rate") == 0)
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strategy->min_comp_rate = val;
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else if (strcmp(def->defname, "first_success_by") == 0)
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strategy->first_success_by = val;
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else if (strcmp(def->defname, "match_size_good") == 0)
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strategy->match_size_good = val;
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else if (strcmp(def->defname, "match_size_drop") == 0)
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strategy->match_size_drop = val;
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}
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return (void *) strategy;
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}
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static struct varlena *
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pglz_cmcompress(CompressionAmOptions *cmoptions, const struct varlena *value)
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{
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int32 valsize,
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len;
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struct varlena *tmp = NULL;
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PGLZ_Strategy *strategy;
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valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
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strategy = (PGLZ_Strategy *) cmoptions->acstate;
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Assert(strategy != NULL);
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if (valsize < strategy->min_input_size ||
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valsize > strategy->max_input_size)
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return NULL;
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tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize) +
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VARHDRSZ_CUSTOM_COMPRESSED);
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len = pglz_compress(VARDATA_ANY(value),
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valsize,
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(char *) tmp + VARHDRSZ_CUSTOM_COMPRESSED,
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strategy);
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if (len >= 0)
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{
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SET_VARSIZE_COMPRESSED(tmp, len + VARHDRSZ_CUSTOM_COMPRESSED);
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return tmp;
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}
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pfree(tmp);
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return NULL;
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}
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static struct varlena *
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pglz_cmdecompress(CompressionAmOptions *cmoptions, const struct varlena *value)
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{
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struct varlena *result;
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int32 resultlen;
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Assert(VARATT_IS_CUSTOM_COMPRESSED(value));
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resultlen = VARRAWSIZE_4B_C(value) + VARHDRSZ;
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result = (struct varlena *) palloc(resultlen);
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SET_VARSIZE(result, resultlen);
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if (pglz_decompress((char *) value + VARHDRSZ_CUSTOM_COMPRESSED,
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VARSIZE(value) - VARHDRSZ_CUSTOM_COMPRESSED,
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VARDATA(result),
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VARRAWSIZE_4B_C(value)) < 0)
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elog(ERROR, "pglz: compressed data is corrupted");
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return result;
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}
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/* pglz is the default compression method */
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Datum
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pglzhandler(PG_FUNCTION_ARGS)
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{
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CompressionAmRoutine *routine = makeNode(CompressionAmRoutine);
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routine->cmcheck = pglz_cmcheck;
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routine->cminitstate = pglz_cminitstate;
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routine->cmcompress = pglz_cmcompress;
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routine->cmdecompress = pglz_cmdecompress;
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PG_RETURN_POINTER(routine);
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}

‎src/include/access/cmapi.h

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -19,7 +19,7 @@
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#include "nodes/pg_list.h"
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2121
#define IsBuiltinCompression(cmid) ((cmid) < FirstBootstrapObjectId)
22-
#define DefaultCompressionOid (InvalidOid)
22+
#define DefaultCompressionOid (PGLZ_AC_OID)
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typedef struct CompressionAmRoutine CompressionAmRoutine;
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‎src/include/catalog/pg_am.dat

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@@ -33,5 +33,8 @@
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{ oid => '3580', oid_symbol => 'BRIN_AM_OID',
3434
descr => 'block range index (BRIN) access method',
3535
amname => 'brin', amhandler => 'brinhandler', amtype => 'i' },
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{ oid => '4002', oid_symbol => 'PGLZ_COMPRESSION_AM_OID',
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descr => 'pglz compression access method',
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amname => 'pglz', amhandler => 'pglzhandler', amtype => 'c' },
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]

‎src/include/catalog/pg_attr_compression.dat

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Original file line numberDiff line numberDiff line change
@@ -18,6 +18,6 @@
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[
2020

21-
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{ acoid => '4002', acname => 'pglz' },
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]

‎src/include/catalog/pg_proc.dat

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@@ -909,6 +909,12 @@
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prorettype => 'void', proargtypes => 'regclass int8',
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prosrc => 'brin_desummarize_range' },
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# Compression access method handlers
913+
{ oid => '4009', descr => 'pglz compression access method handler',
914+
proname => 'pglzhandler', provolatile => 'v',
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prorettype => 'compression_am_handler', proargtypes => 'internal',
916+
prosrc => 'pglzhandler' },
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912918
{ oid => '338', descr => 'validate an operator class',
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proname => 'amvalidate', provolatile => 'v', prorettype => 'bool',
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proargtypes => 'oid', prosrc => 'amvalidate' },

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