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authorvvvv <[email protected]>2024-11-07 12:29:36 +0300
committervvvv <[email protected]>2024-11-07 13:49:47 +0300
commitd4c258e9431675bab6745c8638df6e3dfd4dca6b (patch)
treeb5efcfa11351152a4c872fccaea35749141c0b11 /yql/essentials/parser/pg_wrapper/postgresql/src/include/access/sdir.h
parent13a4f274caef5cfdaf0263b24e4d6bdd5521472b (diff)
Moved other yql/essentials libs YQL-19206
init commit_hash:7d4c435602078407bbf20dd3c32f9c90d2bbcbc0
Diffstat (limited to 'yql/essentials/parser/pg_wrapper/postgresql/src/include/access/sdir.h')
-rw-r--r--yql/essentials/parser/pg_wrapper/postgresql/src/include/access/sdir.h67
1 files changed, 67 insertions, 0 deletions
diff --git a/yql/essentials/parser/pg_wrapper/postgresql/src/include/access/sdir.h b/yql/essentials/parser/pg_wrapper/postgresql/src/include/access/sdir.h
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+++ b/yql/essentials/parser/pg_wrapper/postgresql/src/include/access/sdir.h
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+/*-------------------------------------------------------------------------
+ *
+ * sdir.h
+ * POSTGRES scan direction definitions.
+ *
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/sdir.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef SDIR_H
+#define SDIR_H
+
+
+/*
+ * Defines the direction for scanning a table or an index. Scans are never
+ * invoked using NoMovementScanDirectionScans. For convenience, we use the
+ * values -1 and 1 for backward and forward scans. This allows us to perform
+ * a few mathematical tricks such as what is done in ScanDirectionCombine.
+ */
+typedef enum ScanDirection
+{
+ BackwardScanDirection = -1,
+ NoMovementScanDirection = 0,
+ ForwardScanDirection = 1
+} ScanDirection;
+
+/*
+ * Determine the net effect of two direction specifications.
+ * This relies on having ForwardScanDirection = +1, BackwardScanDirection = -1,
+ * and will probably not do what you want if applied to any other values.
+ */
+#define ScanDirectionCombine(a, b) ((a) * (b))
+
+/*
+ * ScanDirectionIsValid
+ * True iff scan direction is valid.
+ */
+#define ScanDirectionIsValid(direction) \
+ ((bool) (BackwardScanDirection <= (direction) && \
+ (direction) <= ForwardScanDirection))
+
+/*
+ * ScanDirectionIsBackward
+ * True iff scan direction is backward.
+ */
+#define ScanDirectionIsBackward(direction) \
+ ((bool) ((direction) == BackwardScanDirection))
+
+/*
+ * ScanDirectionIsNoMovement
+ * True iff scan direction indicates no movement.
+ */
+#define ScanDirectionIsNoMovement(direction) \
+ ((bool) ((direction) == NoMovementScanDirection))
+
+/*
+ * ScanDirectionIsForward
+ * True iff scan direction is forward.
+ */
+#define ScanDirectionIsForward(direction) \
+ ((bool) ((direction) == ForwardScanDirection))
+
+#endif /* SDIR_H */