From: Shigeru Hanada <hanada@metrosystems.co.jp>
Date: Thu, 18 Nov 2010 08:18:27 +0000 (+0900)
Subject: Simplify the interface of MakeFileState() to make it easier to reuse
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=0a998e548b8d3cf98b7b4a33c06a63cdd26b642e;p=users%2Fhanada%2Fpostgres.git

Simplify the interface of MakeFileState() to make it easier to reuse
file_parser module in COPY FROM.
---

diff --git a/src/backend/foreign/file_fdw.c b/src/backend/foreign/file_fdw.c
index 8cdb090652..33984d467d 100644
--- a/src/backend/foreign/file_fdw.c
+++ b/src/backend/foreign/file_fdw.c
@@ -39,6 +39,9 @@ struct FileFdwOption
 /*
  * Valid options for file_fdw.
  * These options are based on the options for COPY FROM command.
+ *
+ * Note: If you are adding new option for user mapping, you need to modify
+ * fileBeginScan().  See comments of the function for detail.
  */
 static struct FileFdwOption valid_options[] = {
 	/* File options */
@@ -262,17 +265,35 @@ file_fdw_handler(PG_FUNCTION_ARGS)
 
 /*
  * BeginScan()
- *   - initiate access to the file, but we have nothing to do
+ *   - initiate access to the file with creating FileState
+ *
+ * Parameters for parsing file such as filename and format are passed via
+ * generic options of FDW-related objects; foreign-data wrapper, server and
+ * foreign table.  User mapping is not used to get options because there is no
+ * valid option in context of user mapping.
  */
 static void
 fileBeginScan(ForeignScanState *scanstate)
 {
+	ForeignTable   *table;
+	ForeignServer  *server;
+	ForeignDataWrapper *wrapper;
+	List		   *options;
 	FileState		fstate;
 
 	elog(DEBUG2, "%s called", __FUNCTION__);
 
-	/* create FileFdwReply and set default settings */
-	fstate = MakeFileState(scanstate);
+	/* Extract options from FDW objects */
+	table = GetForeignTable(scanstate->ss.ss_currentRelation->rd_id);
+	server = GetForeignServer(table->serverid);
+	wrapper = GetForeignDataWrapper(server->fdwid);
+	options = NIL;
+	options = list_concat(options, wrapper->options);
+	options = list_concat(options, server->options);
+	options = list_concat(options, table->options);
+
+	/* create FileState and set default settings */
+	fstate = MakeFileState(scanstate->ss.ss_currentRelation, options);
 
 	/* pack file information into reply and pass it to subsequent functions */
 	scanstate->reply = (FdwReply *) fstate;
diff --git a/src/backend/foreign/file_parser.c b/src/backend/foreign/file_parser.c
index 924ca0597d..4cabc08c8d 100644
--- a/src/backend/foreign/file_parser.c
+++ b/src/backend/foreign/file_parser.c
@@ -286,17 +286,12 @@ FileLoadRawBuf(FileState fstate)
 
 /*
  * MakeFileState() makes a FileState for a foreign scan on the relation rel.
- *
- * Parameters for parsing file such as filename and format are passed via
- * generic options of FDW-related objects; foreign-data wrapper, server,
- * user mapping and foreign table.
  */
 FileState
-MakeFileState(ForeignScanState *scanstate)
+MakeFileState(Relation rel, List *options)
 {
 	FileState	fstate;
 	bool		format_specified = false;
-	List	   *options;
 	ListCell   *option;
 	TupleDesc	tupDesc;
 	int			num_phys_attrs;
@@ -308,13 +303,7 @@ MakeFileState(ForeignScanState *scanstate)
 	/* Allocate workspace and zero all fields */
 	fstate = (FileStateData *) palloc0(sizeof(FileStateData));
 
-	options = NIL;
-	options = list_concat(options, scanstate->wrapper->options);
-	options = list_concat(options, scanstate->server->options);
-	options = list_concat(options, scanstate->user->options);
-	options = list_concat(options, scanstate->table->options);
-
-	/* Extract options from the statement node tree */
+	/* Extract information about the file and its format from options */
 	foreach(option, options)
 	{
 		DefElem    *defel = (DefElem *) lfirst(option);
@@ -486,7 +475,7 @@ MakeFileState(ForeignScanState *scanstate)
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 errmsg("must be superuser to read from a file")));
 
-	fstate->rel = scanstate->ss.ss_currentRelation;
+	fstate->rel = rel;
 	tupDesc = RelationGetDescr(fstate->rel);
 
 	/* Don't allow read OIDs from a table without them */
@@ -522,7 +511,7 @@ MakeFileState(ForeignScanState *scanstate)
 			if (attrs[i]->attisdropped)
 				continue;
 
-			tuple = SearchSysCache2(ATTNUM, scanstate->table->relid, i + 1);
+			tuple = SearchSysCache2(ATTNUM, rel->rd_id, i + 1);
 			if (!HeapTupleIsValid(tuple))
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),
diff --git a/src/backend/foreign/file_parser.h b/src/backend/foreign/file_parser.h
index fef3052a56..a12f24a930 100644
--- a/src/backend/foreign/file_parser.h
+++ b/src/backend/foreign/file_parser.h
@@ -18,7 +18,7 @@ typedef struct FileStateData *FileState;
 /*
  *
  */
-FileState MakeFileState(ForeignScanState *scanstate);
+FileState MakeFileState(Relation rel, List *options);
 HeapTuple GetNextTuple(FileState cstate, MemoryContext tupleContext);
 void ResetFileState(FileState cstate);
 void FreeFileState(FileState cstate);