diff options
Diffstat (limited to 'src/backend/utils/adt/pg_lzcompress.c')
| -rw-r--r-- | src/backend/utils/adt/pg_lzcompress.c | 32 |
1 files changed, 15 insertions, 17 deletions
diff --git a/src/backend/utils/adt/pg_lzcompress.c b/src/backend/utils/adt/pg_lzcompress.c index 085bc63e0dd..f843232ba64 100644 --- a/src/backend/utils/adt/pg_lzcompress.c +++ b/src/backend/utils/adt/pg_lzcompress.c @@ -166,7 +166,7 @@ * * Copyright (c) 1999-2007, PostgreSQL Global Development Group * - * $PostgreSQL: pgsql/src/backend/utils/adt/pg_lzcompress.c,v 1.26 2007/04/06 04:21:43 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/pg_lzcompress.c,v 1.27 2007/08/04 21:53:00 tgl Exp $ * ---------- */ #include "postgres.h" @@ -211,29 +211,27 @@ typedef struct PGLZ_HistEntry * ---------- */ static const PGLZ_Strategy strategy_default_data = { - 256, /* Data chunks smaller 256 bytes are not - * compressed */ - 6144, /* Data chunks greater equal 6K force - * compression */ - /* except compressed result is greater uncompressed data */ - 20, /* Compression rates below 20% mean fallback - * to uncompressed */ - /* storage except compression is forced by previous parameter */ + 256, /* Data chunks less than 256 bytes are not + * compressed */ + 6144, /* Data chunks >= 6K force compression, unless + * compressed output is larger than input */ + 20, /* Below 6K, compression rates below 20% mean + * fallback to uncompressed */ 128, /* Stop history lookup if a match of 128 bytes - * is found */ + * is found */ 10 /* Lower good match size by 10% at every - * lookup loop iteration. */ + * lookup loop iteration */ }; const PGLZ_Strategy * const PGLZ_strategy_default = &strategy_default_data; static const PGLZ_Strategy strategy_always_data = { - 0, /* Chunks of any size are compressed */ - 0, /* */ - 0, /* We want to save at least one single byte */ + 0, /* Chunks of any size are compressed */ + 0, + 0, /* It's enough to save one single byte */ 128, /* Stop history lookup if a match of 128 bytes - * is found */ - 6 /* Look harder for a good match. */ + * is found */ + 6 /* Look harder for a good match */ }; const PGLZ_Strategy * const PGLZ_strategy_always = &strategy_always_data; @@ -511,7 +509,7 @@ pglz_compress(const char *source, int32 slen, PGLZ_Header *dest, * If the strategy forbids compression (at all or if source chunk too * small), fail. */ - if (strategy->match_size_good == 0 || + if (strategy->match_size_good <= 0 || slen < strategy->min_input_size) return false; |