pg_dump: Simplify internal archive version handling

The ArchiveHandle structure contained the archive format version number
twice, once as a single field and once split into components.  Simplify
that by just keeping the single field and adding some macros to extract
the components.  Introduce some macros for composing version numbers, to
eliminate the repeated use of magic formulas.  Drop the unused trailing
zero byte from the run-time composite version representation.

reviewed by Tom Lane

diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index e237b4a9c901f0595849e5f78a18cf0ef4d64c7a..0e20985350905f6c7dd5537b1a4d659c770eaa85 100644 (file)
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -1105,7 +1105,8 @@ PrintTOCSummary(Archive *AHX)
                        fmtName = "UNKNOWN";
        }
 
-       ahprintf(AH, ";     Dump Version: %d.%d-%d\n", AH->vmaj, AH->vmin, AH->vrev);
+       ahprintf(AH, ";     Dump Version: %d.%d-%d\n",
+                        ARCHIVE_MAJOR(AH->version), ARCHIVE_MINOR(AH->version), ARCHIVE_REV(AH->version));
        ahprintf(AH, ";     Format: %s\n", fmtName);
        ahprintf(AH, ";     Integer: %d bytes\n", (int) AH->intSize);
        ahprintf(AH, ";     Offset: %d bytes\n", (int) AH->offSize);
@@ -2106,6 +2107,7 @@ _discoverArchiveFormat(ArchiveHandle *AH)
        if (strncmp(sig, "PGDMP", 5) == 0)
        {
                int                     byteread;
+               char            vmaj, vmin, vrev;
 
                /*
                 * Finish reading (most of) a custom-format header.
@@ -2115,31 +2117,30 @@ _discoverArchiveFormat(ArchiveHandle *AH)
                if ((byteread = fgetc(fh)) == EOF)
                        READ_ERROR_EXIT(fh);
 
-               AH->vmaj = byteread;
+               vmaj = byteread;
 
                if ((byteread = fgetc(fh)) == EOF)
                        READ_ERROR_EXIT(fh);
 
-               AH->vmin = byteread;
+               vmin = byteread;
 
                /* Save these too... */
-               AH->lookahead[AH->lookaheadLen++] = AH->vmaj;
-               AH->lookahead[AH->lookaheadLen++] = AH->vmin;
+               AH->lookahead[AH->lookaheadLen++] = vmaj;
+               AH->lookahead[AH->lookaheadLen++] = vmin;
 
                /* Check header version; varies from V1.0 */
-               if (AH->vmaj > 1 || ((AH->vmaj == 1) && (AH->vmin > 0)))                /* Version > 1.0 */
+               if (vmaj > 1 || (vmaj == 1 && vmin > 0))                /* Version > 1.0 */
                {
                        if ((byteread = fgetc(fh)) == EOF)
                                READ_ERROR_EXIT(fh);
 
-                       AH->vrev = byteread;
-                       AH->lookahead[AH->lookaheadLen++] = AH->vrev;
+                       vrev = byteread;
+                       AH->lookahead[AH->lookaheadLen++] = vrev;
                }
                else
-                       AH->vrev = 0;
+                       vrev = 0;
 
-               /* Make a convenient integer <maj><min><rev>00 */
-               AH->version = ((AH->vmaj * 256 + AH->vmin) * 256 + AH->vrev) * 256 + 0;
+               AH->version = MAKE_ARCHIVE_VERSION(vmaj, vmin, vrev);
 
                if ((AH->intSize = fgetc(fh)) == EOF)
                        READ_ERROR_EXIT(fh);
@@ -2234,12 +2235,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 
        /* AH->debugLevel = 100; */
 
-       AH->vmaj = K_VERS_MAJOR;
-       AH->vmin = K_VERS_MINOR;
-       AH->vrev = K_VERS_REV;
-
-       /* Make a convenient integer <maj><min><rev>00 */
-       AH->version = ((AH->vmaj * 256 + AH->vmin) * 256 + AH->vrev) * 256 + 0;
+       AH->version = K_VERS_SELF;
 
        /* initialize for backwards compatible string processing */
        AH->public.encoding = 0;        /* PG_SQL_ASCII */
@@ -3528,9 +3524,9 @@ WriteHead(ArchiveHandle *AH)
        struct tm       crtm;
 
        (*AH->WriteBufPtr) (AH, "PGDMP", 5);            /* Magic code */
-       (*AH->WriteBytePtr) (AH, AH->vmaj);
-       (*AH->WriteBytePtr) (AH, AH->vmin);
-       (*AH->WriteBytePtr) (AH, AH->vrev);
+       (*AH->WriteBytePtr) (AH, ARCHIVE_MAJOR(AH->version));
+       (*AH->WriteBytePtr) (AH, ARCHIVE_MINOR(AH->version));
+       (*AH->WriteBytePtr) (AH, ARCHIVE_REV(AH->version));
        (*AH->WriteBytePtr) (AH, AH->intSize);
        (*AH->WriteBytePtr) (AH, AH->offSize);
        (*AH->WriteBytePtr) (AH, AH->format);
@@ -3563,24 +3559,26 @@ ReadHead(ArchiveHandle *AH)
         */
        if (!AH->readHeader)
        {
+               char            vmaj, vmin, vrev;
+
                (*AH->ReadBufPtr) (AH, tmpMag, 5);
 
                if (strncmp(tmpMag, "PGDMP", 5) != 0)
                        exit_horribly(modulename, "did not find magic string in file header\n");
 
-               AH->vmaj = (*AH->ReadBytePtr) (AH);
-               AH->vmin = (*AH->ReadBytePtr) (AH);
+               vmaj = (*AH->ReadBytePtr) (AH);
+               vmin = (*AH->ReadBytePtr) (AH);
 
-               if (AH->vmaj > 1 || ((AH->vmaj == 1) && (AH->vmin > 0)))                /* Version > 1.0 */
-                       AH->vrev = (*AH->ReadBytePtr) (AH);
+               if (vmaj > 1 || (vmaj == 1 && vmin > 0))                /* Version > 1.0 */
+                       vrev = (*AH->ReadBytePtr) (AH);
                else
-                       AH->vrev = 0;
+                       vrev = 0;
 
-               AH->version = ((AH->vmaj * 256 + AH->vmin) * 256 + AH->vrev) * 256 + 0;
+               AH->version = MAKE_ARCHIVE_VERSION(vmaj, vmin, vrev);
 
                if (AH->version < K_VERS_1_0 || AH->version > K_VERS_MAX)
                        exit_horribly(modulename, "unsupported version (%d.%d) in file header\n",
-                                                 AH->vmaj, AH->vmin);
+                                                 vmaj, vmin);
 
                AH->intSize = (*AH->ReadBytePtr) (AH);
                if (AH->intSize > 32)

diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 97d34a52974fbe4502bc67b7e4265c93634fb0ab..50cf452411e5c6e0096cf3aa82827af3a10a2439 100644 (file)
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -62,37 +62,40 @@ typedef struct _z_stream
 typedef z_stream *z_streamp;
 #endif
 
-/* Current archive version number (the format we can output) */
-#define K_VERS_MAJOR 1
-#define K_VERS_MINOR 12
-#define K_VERS_REV 0
-
 /* Data block types */
 #define BLK_DATA 1
 #define BLK_BLOBS 3
 
+/* Encode version components into a convenient integer <maj><min><rev> */
+#define MAKE_ARCHIVE_VERSION(major, minor, rev) (((major) * 256 + (minor)) * 256 + (rev))
+
+#define ARCHIVE_MAJOR(version) (((version) >> 16) & 255)
+#define ARCHIVE_MINOR(version) (((version) >>  8) & 255)
+#define ARCHIVE_REV(version)   (((version)      ) & 255)
+
 /* Historical version numbers (checked in code) */
-#define K_VERS_1_0 (( (1 * 256 + 0) * 256 + 0) * 256 + 0)
-#define K_VERS_1_2 (( (1 * 256 + 2) * 256 + 0) * 256 + 0)              /* Allow No ZLIB */
-#define K_VERS_1_3 (( (1 * 256 + 3) * 256 + 0) * 256 + 0)              /* BLOBs */
-#define K_VERS_1_4 (( (1 * 256 + 4) * 256 + 0) * 256 + 0)              /* Date & name in header */
-#define K_VERS_1_5 (( (1 * 256 + 5) * 256 + 0) * 256 + 0)              /* Handle dependencies */
-#define K_VERS_1_6 (( (1 * 256 + 6) * 256 + 0) * 256 + 0)              /* Schema field in TOCs */
-#define K_VERS_1_7 (( (1 * 256 + 7) * 256 + 0) * 256 + 0)              /* File Offset size in
-                                                                                                                                * header */
-#define K_VERS_1_8 (( (1 * 256 + 8) * 256 + 0) * 256 + 0)              /* change interpretation
-                                                                                                                                * of ID numbers and
-                                                                                                                                * dependencies */
-#define K_VERS_1_9 (( (1 * 256 + 9) * 256 + 0) * 256 + 0)              /* add default_with_oids
-                                                                                                                                * tracking */
-#define K_VERS_1_10 (( (1 * 256 + 10) * 256 + 0) * 256 + 0)            /* add tablespace */
-#define K_VERS_1_11 (( (1 * 256 + 11) * 256 + 0) * 256 + 0)            /* add toc section
-                                                                                                                                * indicator */
-#define K_VERS_1_12 (( (1 * 256 + 12) * 256 + 0) * 256 + 0)            /* add separate BLOB
-                                                                                                                                * entries */
+#define K_VERS_1_0     MAKE_ARCHIVE_VERSION(1, 0, 0)
+#define K_VERS_1_2     MAKE_ARCHIVE_VERSION(1, 2, 0)   /* Allow No ZLIB */
+#define K_VERS_1_3     MAKE_ARCHIVE_VERSION(1, 3, 0)   /* BLOBs */
+#define K_VERS_1_4     MAKE_ARCHIVE_VERSION(1, 4, 0)   /* Date & name in header */
+#define K_VERS_1_5     MAKE_ARCHIVE_VERSION(1, 5, 0)   /* Handle dependencies */
+#define K_VERS_1_6     MAKE_ARCHIVE_VERSION(1, 6, 0)   /* Schema field in TOCs */
+#define K_VERS_1_7     MAKE_ARCHIVE_VERSION(1, 7, 0)   /* File Offset size in header */
+#define K_VERS_1_8     MAKE_ARCHIVE_VERSION(1, 8, 0)   /* change interpretation of ID
+                                                                                                          numbers and dependencies */
+#define K_VERS_1_9     MAKE_ARCHIVE_VERSION(1, 9, 0)   /* add default_with_oids tracking */
+#define K_VERS_1_10    MAKE_ARCHIVE_VERSION(1, 10, 0)  /* add tablespace */
+#define K_VERS_1_11    MAKE_ARCHIVE_VERSION(1, 11, 0)  /* add toc section indicator */
+#define K_VERS_1_12    MAKE_ARCHIVE_VERSION(1, 12, 0)  /* add separate BLOB entries */
+
+/* Current archive version number (the format we can output) */
+#define K_VERS_MAJOR 1
+#define K_VERS_MINOR 12
+#define K_VERS_REV 0
+#define K_VERS_SELF    MAKE_ARCHIVE_VERSION(K_VERS_MAJOR, K_VERS_MINOR, K_VERS_REV);
 
 /* Newest format we can read */
-#define K_VERS_MAX (( (1 * 256 + 12) * 256 + 255) * 256 + 0)
+#define K_VERS_MAX     MAKE_ARCHIVE_VERSION(K_VERS_MAJOR, K_VERS_MINOR, 255)
 
 
 /* Flags to indicate disposition of offsets stored in files */
@@ -205,10 +208,7 @@ typedef enum
 struct _archiveHandle
 {
        Archive         public;                 /* Public part of archive */
-       char            vmaj;                   /* Version of file */
-       char            vmin;
-       char            vrev;
-       int                     version;                /* Conveniently formatted version */
+       int                     version;                /* Version of file */
 
        char       *archiveRemoteVersion;       /* When reading an archive, the
                                                                                 * version of the dumped DB */