Move LockClauseStrength, LockWaitPolicy into new file nodes/lockoptions.h.

tglsfdc · tglsfdc · commit 9fac5fd741ec · 2015-03-15T15:19:04.000-04:00
Commit df630b0 moved enum LockWaitPolicy into its very own header file utils/lockwaitpolicy.h, which does not seem like a great idea from here. First, it's still a node-related declaration, and second, a file named like that can never sensibly be used for anything else. I do not think we want to encourage a one-typedef-per-header-file approach. The upcoming foreign table inheritance patch was doubling down on this bad idea by moving enum LockClauseStrength into its *own* can-never-be-used-for-anything-else file. Instead, let's put them both in a file named nodes/lockoptions.h. (They do seem to need a separate header file because we need them in both parsenodes.h and plannodes.h, and we don't want either of those including the other. Past practice might suggest adding them to nodes/nodes.h, but they don't seem sufficiently globally useful to justify that.) Committed separately since there's no functional change here, just some header-file refactoring.
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
@@ -16,10 +16,10 @@
 
 #include "access/sdir.h"
 #include "access/skey.h"
+#include "nodes/lockoptions.h"
 #include "nodes/primnodes.h"
 #include "storage/bufpage.h"
 #include "storage/lock.h"
-#include "utils/lockwaitpolicy.h"
 #include "utils/relcache.h"
 #include "utils/snapshot.h"
 
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
@@ -16,7 +16,6 @@
 
 #include "executor/execdesc.h"
 #include "nodes/parsenodes.h"
-#include "utils/lockwaitpolicy.h"
 
 
 /*
diff --git a/src/include/nodes/lockoptions.h b/src/include/nodes/lockoptions.h
@@ -0,0 +1,45 @@
+/*-------------------------------------------------------------------------
+ *
+ * lockoptions.h
+ *	  Common header for some locking-related declarations.
+ *
+ *
+ * Copyright (c) 2014-2015, PostgreSQL Global Development Group
+ *
+ * src/include/nodes/lockoptions.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef LOCKOPTIONS_H
+#define LOCKOPTIONS_H
+
+/*
+ * This enum represents the different strengths of FOR UPDATE/SHARE clauses.
+ * The ordering here is important, because the highest numerical value takes
+ * precedence when a RTE is specified multiple ways.  See applyLockingClause.
+ */
+typedef enum LockClauseStrength
+{
+	LCS_FORKEYSHARE,			/* FOR KEY SHARE */
+	LCS_FORSHARE,				/* FOR SHARE */
+	LCS_FORNOKEYUPDATE,			/* FOR NO KEY UPDATE */
+	LCS_FORUPDATE				/* FOR UPDATE */
+} LockClauseStrength;
+
+/*
+ * This enum controls how to deal with rows being locked by FOR UPDATE/SHARE
+ * clauses (i.e., it represents the NOWAIT and SKIP LOCKED options).
+ * The ordering here is important, because the highest numerical value takes
+ * precedence when a RTE is specified multiple ways.  See applyLockingClause.
+ */
+typedef enum LockWaitPolicy
+{
+	/* Wait for the lock to become available (default behavior) */
+	LockWaitBlock,
+	/* Skip rows that can't be locked (SKIP LOCKED) */
+	LockWaitSkip,
+	/* Raise an error if a row cannot be locked (NOWAIT) */
+	LockWaitError
+} LockWaitPolicy;
+
+#endif   /* LOCKOPTIONS_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
@@ -21,9 +21,9 @@
 #define PARSENODES_H
 
 #include "nodes/bitmapset.h"
+#include "nodes/lockoptions.h"
 #include "nodes/primnodes.h"
 #include "nodes/value.h"
-#include "utils/lockwaitpolicy.h"
 
 /* Possible sources of a Query */
 typedef enum QuerySource
@@ -645,15 +645,6 @@ typedef struct DefElem
  * a location field --- currently, parse analysis insists on unqualified
  * names in LockingClause.)
  */
-typedef enum LockClauseStrength
-{
-	/* order is important -- see applyLockingClause */
-	LCS_FORKEYSHARE,
-	LCS_FORSHARE,
-	LCS_FORNOKEYUPDATE,
-	LCS_FORUPDATE
-} LockClauseStrength;
-
 typedef struct LockingClause
 {
 	NodeTag		type;
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
@@ -17,8 +17,8 @@
 #include "access/sdir.h"
 #include "lib/stringinfo.h"
 #include "nodes/bitmapset.h"
+#include "nodes/lockoptions.h"
 #include "nodes/primnodes.h"
-#include "utils/lockwaitpolicy.h"
 
 
 /* ----------------------------------------------------------------
diff --git a/src/include/utils/lockwaitpolicy.h b/src/include/utils/lockwaitpolicy.h
