diff options
Diffstat (limited to 'src/include/utils/pg_lzcompress.h')
| -rw-r--r-- | src/include/utils/pg_lzcompress.h | 79 |
1 files changed, 78 insertions, 1 deletions
diff --git a/src/include/utils/pg_lzcompress.h b/src/include/utils/pg_lzcompress.h index 481fd24fab..9e3d3f3294 100644 --- a/src/include/utils/pg_lzcompress.h +++ b/src/include/utils/pg_lzcompress.h @@ -1,7 +1,7 @@ /* ---------- * pg_lzcompress.h - * - * $Header: /cvsroot/pgsql/src/include/utils/pg_lzcompress.h,v 1.2 1999/11/17 22:18:46 wieck Exp $ + * $Header: /cvsroot/pgsql/src/include/utils/pg_lzcompress.h,v 1.3 1999/11/25 01:28:07 wieck Exp $ * * Definitions for the builtin LZ compressor * ---------- @@ -111,6 +111,26 @@ typedef struct PGLZ_Strategy { /* ---------- + * PGLZ_DecompState - + * + * Decompression state variable for byte-per-byte decompression + * using pglz_decomp_getchar() macro. + * ---------- + */ +typedef struct PGLZ_DecompState { + unsigned char *temp_buf; + unsigned char *cp_in; + unsigned char *cp_end; + unsigned char *cp_out; + unsigned char *cp_copy; + int (*next_char)(struct PGLZ_DecompState *dstate); + int tocopy; + int ctrl_count; + unsigned char ctrl; +} PGLZ_DecompState; + + +/* ---------- * The standard strategies * * PGLZ_strategy_default Starts compression only if input is @@ -140,6 +160,55 @@ extern PGLZ_Strategy *PGLZ_strategy_never; /* ---------- + * pglz_decomp_getchar - + * + * Get next character (or EOF) from decompressor. + * The status variable must be initialized before and deinitialized + * after compression with the next two macros below. + * ---------- + */ +#define pglz_decomp_getchar(_ds) \ + ((*((_ds)->next_char))((_ds))) + + +/* ---------- + * pglz_decomp_init - + * + * Initialize a decomp state from a compressed input. + * ---------- + */ +#define pglz_decomp_init(_ds,_lz) { \ + (_ds)->cp_in = ((unsigned char *)(_lz)) \ + + sizeof(PGLZ_Header); \ + (_ds)->cp_end = (_ds)->cp_in + (_lz)->varsize \ + - sizeof(PGLZ_Header); \ + if (PGLZ_IS_COMPRESSED((_lz))) { \ + (_ds)->temp_buf = (unsigned char *) \ + palloc(PGLZ_RAW_SIZE((_lz))); \ + (_ds)->cp_out = (_ds)->temp_buf; \ + (_ds)->next_char = pglz_get_next_decomp_char_from_lzdata; \ + (_ds)->tocopy = 0; \ + (_ds)->ctrl_count = 0; \ + } else { \ + (_ds)->temp_buf = NULL; \ + (_ds)->next_char = pglz_get_next_decomp_char_from_plain; \ + } \ + } + + +/* ---------- + * pglz_decomp_end - + * + * Deallocate resources after decompression. + * ---------- + */ +#define pglz_decomp_end(_ds) { \ + if ((_ds)->temp_buf != NULL) \ + pfree((void *)((_ds)->temp_buf)); \ + } + + +/* ---------- * Global function declarations * ---------- */ @@ -148,5 +217,13 @@ int pglz_compress (char *source, int32 slen, PGLZ_Header *dest, int pglz_decompress (PGLZ_Header *source, char *dest); +/* ---------- + * Functions used by pglz_decomp_getchar(). + * Internal use only. + * ---------- + */ +extern int pglz_get_next_decomp_char_from_lzdata(PGLZ_DecompState *dstate); +extern int pglz_get_next_decomp_char_from_plain(PGLZ_DecompState *dstate); + #endif /* _PG_LZCOMPRESS_H_ */ |