Introduce JSON based annotation parsing

src/backend/distributed/utils/attribute.c

@@ -15,6 +15,8 @@
 #include "distributed/log_utils.h"
 #include "distributed/listutils.h"
 #include "distributed/metadata_cache.h"
+#include "distributed/jsonbutils.h"
+#include "distributed/colocation_utils.h"
 #include "distributed/tuplestore.h"
 #include "executor/execdesc.h"
 #include "storage/ipc.h"
@@ -22,7 +24,7 @@
 #include "storage/shmem.h"
 #include <sys/time.h>
 #include "utils/builtins.h"
-
+#include "utils/json.h"
 #include "distributed/utils/attribute.h"
 
 #include <time.h>
@@ -31,8 +33,8 @@ static void AttributeMetricsIfApplicable(void);
 
 ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
 
-#define ATTRIBUTE_PREFIX "/* attributeTo: "
+#define ATTRIBUTE_PREFIX "/*{"
-#define ATTRIBUTE_STRING_FORMAT "/* attributeTo: %s,%d */"
+#define ATTRIBUTE_STRING_FORMAT "/*{\"tId\":%s,\"cId\":%d}*/"
 #define CITUS_STATS_TENANTS_COLUMNS 7
 #define ONE_QUERY_SCORE 1000000000
 
@@ -62,6 +64,7 @@ static void MultiTenantMonitorSMInit(void);
 static int CreateTenantStats(MultiTenantMonitor *monitor, time_t queryTime);
 static int FindTenantStats(MultiTenantMonitor *monitor);
 static size_t MultiTenantMonitorshmemSize(void);
+static char * extractTopComment(const char *inputString);
 
 int MultiTenantMonitoringLogLevel = CITUS_LOG_LEVEL_OFF;
 int CitusStatsTenantsPeriod = (time_t) 60;
@@ -198,54 +201,27 @@ AttributeQueryIfAnnotated(const char *query_string, CmdType commandType)
 		return;
 	}
 
-	if (strncmp(ATTRIBUTE_PREFIX, query_string, strlen(ATTRIBUTE_PREFIX)) == 0)
+	char *annotation = extractTopComment(query_string);
+	if (annotation != NULL)
 	{
-		/* TODO create a function to safely parse the tenant identifier from the query comment */
+		Datum jsonbDatum = DirectFunctionCall1(jsonb_in, PointerGetDatum(annotation));
-		/* query is attributed to a tenant */
-		char *tenantId = (char *) query_string + strlen(ATTRIBUTE_PREFIX);
-		char *tenantEnd = tenantId;
-		while (true && tenantEnd[0] != '\0')
-		{
-			if (tenantEnd[0] == ' ' && tenantEnd[1] == '*' && tenantEnd[2] == '/')
-			{
-				break;
-			}
 
-			tenantEnd++;
+		text *tenantIdTextP = ExtractFieldTextP(jsonbDatum, "tId");
-		}
+		if (tenantIdTextP != NULL)
-		tenantEnd--;
-
-		colocationGroupId = 0;
-		while (*tenantEnd != ',')
 		{
-			colocationGroupId *= 10;
+			char *tenantId = text_to_cstring(tenantIdTextP);
-			colocationGroupId += *tenantEnd - '0';
+			strcpy_s(attributeToTenant, sizeof(attributeToTenant), tenantId);
-			tenantEnd--;
 		}
 
-		int t = colocationGroupId;
+		colocationGroupId = ExtractFieldInt32(jsonbDatum, "cId", INVALID_COLOCATION_ID);
-		colocationGroupId = 0;
-		while (t)
-		{
-			colocationGroupId *= 10;
-			colocationGroupId += t % 10;
-			t /= 10;
-		}
-
-		/* hack to get a clean copy of the tenant id string */
-		char tenantEndTmp = *tenantEnd;
-		*tenantEnd = '\0';
-		tenantId = pstrdup(tenantId);
-		*tenantEnd = tenantEndTmp;
 
 		if (MultiTenantMonitoringLogLevel != CITUS_LOG_LEVEL_OFF)
 		{
-			ereport(NOTICE, (errmsg("attributing query to tenant: %s",
+			ereport(NOTICE, (errmsg(
-									quote_literal_cstr(tenantId))));
+								 "attributing query to tenant: %s, colocationGroupId: %d",
+								 quote_literal_cstr(attributeToTenant),
+								 colocationGroupId)));
 		}
-
-		strcpy_s(attributeToTenant, sizeof(attributeToTenant), tenantId);
-		attributeToTenantStart = clock();
 	}
 	else
 	{
@@ -253,6 +229,7 @@ AttributeQueryIfAnnotated(const char *query_string, CmdType commandType)
 	}
 
 	/*DetachSegment(); */
+	attributeToTenantStart = clock();
 }
 
 
@@ -266,9 +243,13 @@ AnnotateQuery(char *queryString, char *partitionColumn, int colocationId)
 	{
 		return queryString;
 	}
-	StringInfo newQuery = makeStringInfo();
-	appendStringInfo(newQuery, ATTRIBUTE_STRING_FORMAT, partitionColumn, colocationId);
 
+	StringInfo escapedSourceName = makeStringInfo();
+	escape_json(escapedSourceName, partitionColumn);
+
+	StringInfo newQuery = makeStringInfo();
+	appendStringInfo(newQuery, ATTRIBUTE_STRING_FORMAT, escapedSourceName->data,
+					 colocationId);
 	appendStringInfoString(newQuery, queryString);
 
 	return newQuery->data;
@@ -686,3 +667,35 @@ MultiTenantMonitorshmemSize(void)
 
 	return size;
 }
+
+
+/*
+ * extractTopComment extracts the top-level multi-line comment from a given input string.
+ */
+static char *
+extractTopComment(const char *inputString)
+{
+	int i = 0;
+
+	/* If query starts with a comment */
+	if (inputString[i] == '/' && inputString[i + 1] == '*')
+	{
+		/* Skip the comment start characters */
+		i += 2;
+		while (inputString[i] && (inputString[i] != '*' && inputString[i + 1] != '/'))
+		{
+			i++;
+		}
+	}
+
+	if (i > 2)
+	{
+		char *result = (char *) malloc(sizeof(char) * (i - 1));
+		strncpy(result, inputString + 2, i - 2);
+		return result;
+	}
+	else
+	{
+		return NULL;
+	}
+}