Add pgLsnFromStr(), pgLsnToStr(), and pgLsnToWalSegment().

src/postgres/interface.c

@@ -571,6 +571,53 @@ pgTablespaceId(unsigned int pgVersion)
     FUNCTION_TEST_RETURN(result);
 }
 
+/**********************************************************************************************************************************/
+uint64_t
+pgLsnFromStr(const String *lsn)
+{
+    FUNCTION_TEST_BEGIN();
+        FUNCTION_TEST_PARAM(STRING, lsn);
+    FUNCTION_TEST_END();
+
+    uint64_t result = 0;
+
+    MEM_CONTEXT_TEMP_BEGIN()
+    {
+        StringList *lsnPart = strLstNewSplit(lsn, FSLASH_STR);
+
+        CHECK(strLstSize(lsnPart) == 2);
+
+        result = (cvtZToUInt64Base(strPtr(strLstGet(lsnPart, 0)), 16) << 32) + cvtZToUInt64Base(strPtr(strLstGet(lsnPart, 1)), 16);
+    }
+    MEM_CONTEXT_TEMP_END();
+
+    FUNCTION_TEST_RETURN(result);
+}
+
+String *
+pgLsnToStr(uint64_t lsn)
+{
+    FUNCTION_TEST_BEGIN();
+        FUNCTION_TEST_PARAM(UINT64, lsn);
+    FUNCTION_TEST_END();
+
+    FUNCTION_TEST_RETURN(strNewFmt("%x/%x", (unsigned int)(lsn >> 32), (unsigned int)(lsn & 0xFFFFFFFF)));
+}
+
+/**********************************************************************************************************************************/
+String *
+pgLsnToWalSegment(uint32_t timeline, uint64_t lsn, unsigned int walSegmentSize)
+{
+    FUNCTION_TEST_BEGIN();
+        FUNCTION_TEST_PARAM(UINT, timeline);
+        FUNCTION_TEST_PARAM(UINT64, lsn);
+        FUNCTION_TEST_PARAM(UINT, walSegmentSize);
+    FUNCTION_TEST_END();
+
+    FUNCTION_TEST_RETURN(
+        strNewFmt("%08X%08X%08X", timeline, (unsigned int)(lsn >> 32), (unsigned int)(lsn & 0xFFFFFFFF / walSegmentSize)));
+}
+
 /**********************************************************************************************************************************/
 const String *
 pgLsnName(unsigned int pgVersion)

src/postgres/interface.h

@@ -125,6 +125,13 @@ PgWal pgWalFromBuffer(const Buffer *walBuffer);
 // Get the tablespace identifier used to distinguish versions in a tablespace directory, e.g. PG_9.0_201008051
 String *pgTablespaceId(unsigned int pgVersion);
 
+// Convert a string to an lsn and vice versa
+uint64_t pgLsnFromStr(const String *lsn);
+String *pgLsnToStr(uint64_t lsn);
+
+// Convert a timeline and lsn to a wal segment
+String *pgLsnToWalSegment(uint32_t timeline, uint64_t lsn, unsigned int walSegmentSize);
+
 // Get name used for lsn in functions (this was changed in PostgreSQL 10 for consistency since lots of names were changing)
 const String *pgLsnName(unsigned int pgVersion);
 

test/define.yaml

@@ -342,7 +342,7 @@ unit:
 
       # ----------------------------------------------------------------------------------------------------------------------------
       - name: interface
-        total: 7
+        total: 8
 
         coverage:
           postgres/interface: full

test/src/module/postgres/interfaceTest.c

@@ -101,6 +101,21 @@ testRun(void)
         TEST_RESULT_INT(info.version, PG_VERSION_83, "   check version");
     }
 
+    // *****************************************************************************************************************************
+    if (testBegin("pgLsnFromStr(), pgLsnToStr(), and pgLsnToWalSegment()"))
+    {
+        TEST_RESULT_UINT(pgLsnFromStr(STRDEF("1/1")), 0x0000000100000001, "lsn to string");
+        TEST_RESULT_UINT(pgLsnFromStr(STRDEF("ffffffff/ffffffff")), 0xFFFFFFFFFFFFFFFF, "lsn to string");
+        TEST_RESULT_UINT(pgLsnFromStr(STRDEF("ffffffff/aaaaaaaa")), 0xFFFFFFFFAAAAAAAA, "lsn to string");
+
+        TEST_RESULT_STR_Z(pgLsnToStr(0xFFFFFFFFAAAAAAAA), "ffffffff/aaaaaaaa", "string to lsn");
+        TEST_RESULT_STR_Z(pgLsnToStr(0x0000000000000000), "0/0", "string to lsn");
+        TEST_RESULT_STR_Z(pgLsnToStr(0x0000000100000002), "1/2", "string to lsn");
+
+        TEST_RESULT_STR_Z(pgLsnToWalSegment(1, 0xFFFFFFFFAAAAAAAA, 0x1000000), "00000001FFFFFFFF000000AA", "lsn to wal segment");
+        TEST_RESULT_STR_Z(pgLsnToWalSegment(1, 0xFFFFFFFFAAAAAAAA, 0x40000000), "00000001FFFFFFFF00000002", "lsn to wal segment");
+    }
+
     // *****************************************************************************************************************************
     if (testBegin("pgLsnName(), pgTablespaceId(), pgWalName(), and pgXactPath()"))
     {