Fix up bad layout of some comments (probably pg_indent's fault), and

improve grammar a tad.  Per Greg Stark.

diff --git a/src/backend/utils/adt/pg_lzcompress.c b/src/backend/utils/adt/pg_lzcompress.c
index 085bc63e0dd0e6d1326296c1202aeb6b07fb2065..f843232ba6440a563947d8294e7d6ac70521cf35 100644 (file)
--- 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;
 

diff --git a/src/include/utils/pg_lzcompress.h b/src/include/utils/pg_lzcompress.h
index bed75d9af17e8b5d949ead8f73f80f2e697a37c7..fdd9701ee0ea580b0da0eb39038ed9a434ca3bcb 100644 (file)
--- a/src/include/utils/pg_lzcompress.h
+++ b/src/include/utils/pg_lzcompress.h
@@ -3,7 +3,7 @@
  *
  * Definitions for the builtin LZ compressor
  *
- * $PostgreSQL: pgsql/src/include/utils/pg_lzcompress.h,v 1.14 2007/02/27 23:48:10 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/pg_lzcompress.h,v 1.15 2007/08/04 21:53:00 tgl Exp $
  * ----------
  */
 
@@ -50,16 +50,18 @@ typedef struct PGLZ_Header
  *
  *     min_input_size      Minimum input data size to start compression.
  *
- *     force_input_size    Input data size at which compressed storage is
- *                         forced even if the compression rate drops below
- *                         min_comp_rate (but not below 0).
- *
- *     min_comp_rate       Minimum compression rate (0-99%), the output
- *                         must be smaller than the input. If that isn't
+ *     force_input_size    Minimum input data size to force compression
+ *                         even if the compression rate drops below
+ *                         min_comp_rate.  But in any case the output
+ *                         must be smaller than the input.  If that isn't
  *                         the case, the compressor will throw away its
  *                         output and copy the original, uncompressed data
  *                         to the output buffer.
  *
+ *     min_comp_rate       Minimum compression rate (0-99%) to require for
+ *                         inputs smaller than force_input_size.  If not
+ *                         achieved, the output will be uncompressed.
+ *
  *     match_size_good     The initial GOOD match size when starting history
  *                         lookup. When looking up the history to find a
  *                         match that could be expressed as a tag, the
@@ -70,8 +72,8 @@ typedef struct PGLZ_Header
  *                         longer the lookup takes, the smaller matches
  *                         are considered good.
  *
- *     match_size_drop     The percentage, match_size_good is lowered
- *                         at each history check. Allowed values are
+ *     match_size_drop     The percentage by which match_size_good is lowered
+ *                         after each history check. Allowed values are
  *                         0 (no change until end) to 100 (only check
  *                         latest history entry at all).
  * ----------