Add cfs_fragmentation function

knizhnik · knizhnik · commit c5037c7dbc2f · 2016-11-17T18:10:50.000+03:00
diff --git a/src/backend/storage/file/cfs.c b/src/backend/storage/file/cfs.c
@@ -702,10 +702,11 @@ static bool cfs_gc_file(char* map_path)
 		endTime = GetCurrentTimestamp();
 		TimestampDifference(startTime, endTime, &secs, &usecs);
 
-		elog(LOG, "%d: defragment file %s: old size %d, new size %d, logical size %d, used %d, compression ratio %f, time %ld usec",
-			 MyProcPid, file_path, physSize, newSize, virtSize, usedSize, (double)virtSize/newSize,
-			 secs*USECS_PER_SEC + usecs);
-
+		if (succeed) { 
+			elog(LOG, "%d: defragment file %s: old size %d, new size %d, logical size %d, used %d, compression ratio %f, time %ld usec",
+				 MyProcPid, file_path, physSize, newSize, virtSize, usedSize, (double)virtSize/newSize,
+				 secs*USECS_PER_SEC + usecs);
+		}
 		pfree(file_path);
 		pfree(file_bck_path);
 		pfree(map_bck_path);
@@ -839,6 +840,7 @@ PG_FUNCTION_INFO_V1(cfs_enable_gc);
 PG_FUNCTION_INFO_V1(cfs_version);
 PG_FUNCTION_INFO_V1(cfs_estimate);
 PG_FUNCTION_INFO_V1(cfs_compression_ratio);
+PG_FUNCTION_INFO_V1(cfs_fragmentation);
 PG_FUNCTION_INFO_V1(cfs_gc_activity_processed_bytes);
 PG_FUNCTION_INFO_V1(cfs_gc_activity_processed_pages);
 PG_FUNCTION_INFO_V1(cfs_gc_activity_processed_files);
@@ -985,6 +987,55 @@ Datum cfs_compression_ratio(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8((double)virtSize/physSize);
 }
 
+Datum cfs_fragmentation(PG_FUNCTION_ARGS)
+{
+    Oid oid =  PG_GETARG_OID(0);
+    Relation rel = try_relation_open(oid, AccessShareLock);
+	uint64 usedSize = 0;
+	uint64 physSize = 0;
+
+    if (rel != NULL) {
+        char* path = relpathbackend(rel->rd_node, rel->rd_backend, MAIN_FORKNUM);
+        char* map_path = (char*)palloc(strlen(path) + 16);
+        int i = 0;
+
+        while (true) {
+            int md;
+			FileMap* map;
+
+            if (i == 0) {
+                sprintf(map_path, "%s.cfm", path);
+            } else {
+                sprintf(map_path, "%s.%u.cfm", path, i);
+            }
+			md = open(map_path, O_RDWR|PG_BINARY, 0);
+            if (md < 0) {
+				break;
+			}
+			map = cfs_mmap(md);
+			if (map == MAP_FAILED) {
+				elog(LOG, "cfs_compression_ration failed to map file %s: %m", map_path);
+				close(md);
+				break;
+			}
+			usedSize += pg_atomic_read_u32(&map->usedSize);
+			physSize += pg_atomic_read_u32(&map->physSize);
+			
+			if (cfs_munmap(map) < 0) {
+				elog(LOG, "Failed to unmap file %s: %m", map_path);
+			}
+			if (close(md) < 0) {
+				elog(LOG, "Failed to close file %s: %m", map_path);
+			}
+			i += 1;
+		}
+		pfree(path);
+		pfree(map_path);
+		relation_close(rel, AccessShareLock);
+	}
+	PG_RETURN_FLOAT8((double)physSize/usedSize);
+}
+
 Datum cfs_gc_activity_processed_bytes(PG_FUNCTION_ARGS)
 {
 	PG_RETURN_INT64(cfs_state->gc_stat.processedBytes);
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
@@ -5358,6 +5358,8 @@ DATA(insert OID = 6107 (  cfs_gc_activity_processed_pages		   PGNSP PGUID 12 1 0
 DESCR("Number of transferred  pages by CFS garbage collectors since system start");
 DATA(insert OID = 6108 (  cfs_gc_activity_scanned_files		   PGNSP PGUID 12 1 0 0 0 f f f f t f v s 0 0 20 "" _null_ _null_ _null_ _null_ _null_ cfs_gc_activity_scanned_files _null_ _null_ _null_ ));
 DESCR("Number of files scanned by CFS garbage collectors since system start");
+DATA(insert OID = 6109 (  cfs_fragmentation  PGNSP PGUID 12 1 0 0 0 f f f f t f v s 1 0 701 "2205" _null_ _null_ _null_ _null_ _null_ cfs_fragmentation _null_ _null_ _null_ ));
+DESCR("Fragmentation level of relation");
 
 /* distance functions */
 DATA(insert OID = 3343 ( int2_dist		PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0   21 "21 21"		_null_ _null_ _null_ _null_ _null_	int2_dist	_null_ _null_ _null_ ));
