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9fb9691a88
Compilers that don't understand that elog(ERROR) doesn't return issued warnings here. In the cases in libpq_pipeline.c, we were not exactly helping things by failing to mark pg_fatal() as noreturn. Per buildfarm.
125 lines
3.6 KiB
C
125 lines
3.6 KiB
C
/*-------------------------------------------------------------------------
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*
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* toast_compression.h
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* Functions for toast compression.
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*
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* Copyright (c) 2021, PostgreSQL Global Development Group
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*
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* src/include/access/toast_compression.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef TOAST_COMPRESSION_H
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#define TOAST_COMPRESSION_H
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#include "utils/guc.h"
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/* GUCs */
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extern char *default_toast_compression;
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/* default compression method if not specified. */
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#define DEFAULT_TOAST_COMPRESSION "pglz"
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/*
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* Built-in compression method-id. The toast compression header will store
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* this in the first 2 bits of the raw length. These built-in compression
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* method-id are directly mapped to the built-in compression methods.
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*/
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typedef enum ToastCompressionId
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{
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TOAST_PGLZ_COMPRESSION_ID = 0,
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TOAST_LZ4_COMPRESSION_ID = 1,
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TOAST_INVALID_COMPRESSION_ID = 2
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} ToastCompressionId;
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/*
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* Built-in compression methods. pg_attribute will store this in the
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* attcompression column.
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*/
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#define TOAST_PGLZ_COMPRESSION 'p'
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#define TOAST_LZ4_COMPRESSION 'l'
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#define InvalidCompressionMethod '\0'
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#define CompressionMethodIsValid(cm) ((bool) ((cm) != InvalidCompressionMethod))
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#define NO_LZ4_SUPPORT() \
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ereport(ERROR, \
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), \
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errmsg("unsupported LZ4 compression method"), \
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errdetail("This functionality requires the server to be built with lz4 support."), \
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errhint("You need to rebuild PostgreSQL using --with-lz4.")))
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#define IsValidCompression(cm) ((cm) != InvalidCompressionMethod)
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#define IsStorageCompressible(storage) ((storage) != TYPSTORAGE_PLAIN && \
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(storage) != TYPSTORAGE_EXTERNAL)
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/*
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* GetCompressionMethodName - Get compression method name
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*/
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static inline const char *
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GetCompressionMethodName(char method)
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{
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switch (method)
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{
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case TOAST_PGLZ_COMPRESSION:
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return "pglz";
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case TOAST_LZ4_COMPRESSION:
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return "lz4";
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default:
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elog(ERROR, "invalid compression method %c", method);
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return NULL; /* keep compiler quiet */
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}
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}
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/*
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* CompressionNameToMethod - Get compression method from compression name
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*
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* Search in the available built-in methods. If the compression not found
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* in the built-in methods then return InvalidCompressionMethod.
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*/
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static inline char
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CompressionNameToMethod(char *compression)
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{
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if (strcmp(compression, "pglz") == 0)
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return TOAST_PGLZ_COMPRESSION;
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else if (strcmp(compression, "lz4") == 0)
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{
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#ifndef USE_LZ4
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NO_LZ4_SUPPORT();
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#endif
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return TOAST_LZ4_COMPRESSION;
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}
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return InvalidCompressionMethod;
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}
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/*
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* GetDefaultToastCompression -- get the default toast compression method
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*
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* This exists to hide the use of the default_toast_compression GUC variable.
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*/
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static inline char
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GetDefaultToastCompression(void)
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{
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return CompressionNameToMethod(default_toast_compression);
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}
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/* pglz compression/decompression routines */
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extern struct varlena *pglz_compress_datum(const struct varlena *value);
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extern struct varlena *pglz_decompress_datum(const struct varlena *value);
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extern struct varlena *pglz_decompress_datum_slice(const struct varlena *value,
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int32 slicelength);
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/* lz4 compression/decompression routines */
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extern struct varlena *lz4_compress_datum(const struct varlena *value);
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extern struct varlena *lz4_decompress_datum(const struct varlena *value);
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extern struct varlena *lz4_decompress_datum_slice(const struct varlena *value,
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int32 slicelength);
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extern ToastCompressionId toast_get_compression_id(struct varlena *attr);
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extern bool check_default_toast_compression(char **newval, void **extra,
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GucSource source);
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#endif /* TOAST_COMPRESSION_H */
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