Add cfs_compression_ratio function

knizhnik · knizhnik · commit c1a6f4f5b355 · 2016-11-10T10:04:14.000+03:00
diff --git a/src/backend/storage/file/cfs.c b/src/backend/storage/file/cfs.c
@@ -831,6 +831,7 @@ PG_FUNCTION_INFO_V1(cfs_start_gc);
 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);
 
 Datum cfs_start_gc(PG_FUNCTION_ARGS)
 {
@@ -923,3 +924,53 @@ Datum cfs_estimate(PG_FUNCTION_ARGS)
 	}
 	PG_RETURN_FLOAT8(avgRatio);
 }
+
+Datum cfs_compression_ratio(PG_FUNCTION_ARGS)
+{
+    Oid oid =  PG_GETARG_OID(0);
+    Relation rel = try_relation_open(oid, AccessShareLock);
+	uint64 virtSize = 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_RDONLY|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;
+			}
+			virtSize += pg_atomic_read_u32(&map->virtSize);
+			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)virtSize/physSize);
+}
+
diff --git a/src/backend/storage/file/reinit.c b/src/backend/storage/file/reinit.c
@@ -431,7 +431,7 @@ parse_filename_for_nontemp_relation(const char *name, int *oidchars,
 		int			segchar;
 
 		/* .cfm is used by compression */
-		if (strcmp(name+pos+1, "cfm") == 0) {
+		if (strcmp(name+pos, ".cfm") == 0) {
 			return true;
 		}
 		for (segchar = 1; isdigit((unsigned char) name[pos + segchar]); ++segchar)
@@ -441,6 +441,11 @@ parse_filename_for_nontemp_relation(const char *name, int *oidchars,
 		pos += segchar;
 	}
 
+	/* .cfm is used by compression */
+	if (strcmp(name+pos, ".cfm") == 0) {
+		return true;
+	}
+
 	/* Now we should be at the end. */
 	if (name[pos] != '\0')
 		return false;
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
@@ -5348,6 +5348,8 @@ DATA(insert OID = 6102 (  cfs_enable_gc		   PGNSP PGUID 12 1 0 0 0 f f f f t f v
 DESCR("Enable or disable CFS garbage collection");
 DATA(insert OID = 6103 (  cfs_estimate		   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_estimate _null_ _null_ _null_ ));
 DESCR("Estimate relation compression ratio");
+DATA(insert OID = 6019 (  cfs_compression_ratio  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_compression_ratio _null_ _null_ _null_ ));
+DESCR("Compression ration 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_ ));
