Add pgControlInfo() to read pg_control and determine the PostgreSQL version.

src/postgres/info.c

@@ -0,0 +1,77 @@
+/***********************************************************************************************************************************
+PostgreSQL Info
+***********************************************************************************************************************************/
+#include "common/memContext.h"
+#include "postgres/info.h"
+#include "postgres/type.h"
+#include "postgres/version.h"
+#include "storage/helper.h"
+
+/***********************************************************************************************************************************
+Map control/catalog version to PostgreSQL version
+***********************************************************************************************************************************/
+static uint
+pgVersionMap(uint32_t controlVersion, uint32_t catalogVersion)
+{
+    uint result = 0;
+
+    if (controlVersion == 1002 && catalogVersion == 201707211)
+        result = PG_VERSION_10;
+    else if (controlVersion == 960 && catalogVersion == 201608131)
+        result = PG_VERSION_96;
+    else if (controlVersion == 942 && catalogVersion == 201510051)
+        result = PG_VERSION_95;
+    else if (controlVersion == 942 && catalogVersion == 201409291)
+        result = PG_VERSION_94;
+    else if (controlVersion == 937 && catalogVersion == 201306121)
+        result = PG_VERSION_93;
+    else if (controlVersion == 922 && catalogVersion == 201204301)
+        result = PG_VERSION_92;
+    else if (controlVersion == 903 && catalogVersion == 201105231)
+        result = PG_VERSION_91;
+    else if (controlVersion == 903 && catalogVersion == 201008051)
+        result = PG_VERSION_90;
+    else if (controlVersion == 843 && catalogVersion == 200904091)
+        result = PG_VERSION_84;
+    else if (controlVersion == 833 && catalogVersion == 200711281)
+        result = PG_VERSION_83;
+    else
+    {
+        THROW(
+            VersionNotSupportedError,
+            "unexpected control version = %u and catalog version = %u\n"
+                "HINT: is this version of PostgreSQL supported?",
+            controlVersion, catalogVersion);
+    }
+
+    return result;
+}
+
+/***********************************************************************************************************************************
+Get info from pg_control
+***********************************************************************************************************************************/
+PgControlInfo
+pgControlInfo(const String *pgPath)
+{
+    PgControlInfo result = {0};
+
+    MEM_CONTEXT_TEMP_BEGIN()
+    {
+        // Open control file for read
+        StorageFileRead *controlRead = storageNewReadNP(
+            storageLocal(), strNewFmt("%s/" PG_PATH_GLOBAL "/" PG_FILE_PGCONTROL, strPtr(pgPath)));
+        storageFileReadOpen(controlRead);
+
+        // Read contents
+        PgControlFile *control = (PgControlFile *)bufPtr(storageFileRead(controlRead));
+
+        // Copy to result structure and get PostgreSQL version
+        result.systemId = control->systemId;
+        result.controlVersion = control->controlVersion;
+        result.catalogVersion = control->catalogVersion;
+        result.version = pgVersionMap(result.controlVersion, result.catalogVersion);
+    }
+    MEM_CONTEXT_TEMP_END();
+
+    return result;
+}

src/postgres/info.h

@@ -0,0 +1,28 @@
+/***********************************************************************************************************************************
+PostgreSQL Info
+***********************************************************************************************************************************/
+#ifndef POSTGRES_INFO_H
+#define POSTGRES_INFO_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+/***********************************************************************************************************************************
+PostgreSQL Control File Info
+***********************************************************************************************************************************/
+typedef struct PgControlInfo
+{
+    uint64_t systemId;
+    uint32_t controlVersion;
+    uint32_t catalogVersion;
+    uint version;
+} PgControlInfo;
+
+#include "common/type/string.h"
+
+/***********************************************************************************************************************************
+Functions
+***********************************************************************************************************************************/
+PgControlInfo pgControlInfo(const String *pgPath);
+
+#endif

src/postgres/type.h

@@ -0,0 +1,24 @@
+/***********************************************************************************************************************************
+PostreSQL Types
+***********************************************************************************************************************************/
+#ifndef POSTGRES_TYPE_H
+#define POSTGRES_TYPE_H
+
+/***********************************************************************************************************************************
+Defines for various Postgres paths and files
+***********************************************************************************************************************************/
+#define PG_FILE_PGCONTROL                                           "pg_control"
+
+#define PG_PATH_GLOBAL                                              "global"
+
+/***********************************************************************************************************************************
+pg_control file data
+***********************************************************************************************************************************/
+typedef struct PgControlFile
+{
+    uint64_t systemId;
+    uint32_t controlVersion;
+    uint32_t catalogVersion;
+} PgControlFile;
+
+#endif

src/postgres/version.h

@@ -0,0 +1,22 @@
+/***********************************************************************************************************************************
+PostreSQL Version Constants
+***********************************************************************************************************************************/
+#ifndef POSTGRES_VERSION_H
+#define POSTGRES_VERSION_H
+
+/***********************************************************************************************************************************
+PostgreSQL version constants
+***********************************************************************************************************************************/
+#define PG_VERSION_83                                                80300
+#define PG_VERSION_84                                                80400
+#define PG_VERSION_90                                                90000
+#define PG_VERSION_91                                                90100
+#define PG_VERSION_92                                                90200
+#define PG_VERSION_93                                                90300
+#define PG_VERSION_94                                                90400
+#define PG_VERSION_95                                                90500
+#define PG_VERSION_96                                                90600
+#define PG_VERSION_10                                               100000
+#define PG_VERSION_11                                               110000
+
+#endif