WT-2375 Added tests using revint, a reverse integer collator for testing.

Revint demonstrates how collators are expected to decode non-trivial key
formats and work in situations with duplicate keys.  The new test uses
both a collator and an extractor.

2 files changed, 167 insertions, 0 deletions

diff --git a/ext/collators/revint/Makefile.am b/ext/collators/revint/Makefile.am
new file mode 100644
index 00000000000..8c85c6a4701
--- /dev/null
+++ b/ext/collators/revint/Makefile.am
@@ -0,0 +1,10 @@
+AM_CPPFLAGS = -I$(top_builddir) -I$(top_srcdir)/src/include
+
+noinst_LTLIBRARIES = libwiredtiger_revint_collator.la
+libwiredtiger_revint_collator_la_SOURCES = revint_collator.c
+
+# libtool hack: noinst_LTLIBRARIES turns off building shared libraries as well
+# as installation, it will only build static libraries.  As far as I can tell,
+# the "approved" libtool way to turn them back on is by adding -rpath.
+libwiredtiger_revint_collator_la_LDFLAGS = \
+	-avoid-version -module -rpath /nowhere
diff --git a/ext/collators/revint/revint_collator.c b/ext/collators/revint/revint_collator.c
new file mode 100644
index 00000000000..ac4a51970bb
--- /dev/null
+++ b/ext/collators/revint/revint_collator.c
@@ -0,0 +1,157 @@
+/*-
+ * Public Domain 2014-2016 MongoDB, Inc.
+ * Public Domain 2008-2014 WiredTiger, Inc.
+ *
+ * This is free and unencumbered software released into the public domain.
+ *
+ * Anyone is free to copy, modify, publish, use, compile, sell, or
+ * distribute this software, either in source code form or as a compiled
+ * binary, for any purpose, commercial or non-commercial, and by any
+ * means.
+ *
+ * In jurisdictions that recognize copyright laws, the author or authors
+ * of this software dedicate any and all copyright interest in the
+ * software to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and
+ * successors. We intend this dedication to be an overt act of
+ * relinquishment in perpetuity of all present and future rights to this
+ * software under copyright law.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+
+#include <wiredtiger_ext.h>
+#include <errno.h>
+#include <stdint.h>
+
+/*
+ * Set up a collator used with indices having a single integer key,
+ * where the ordering is descending (reversed).
+ */
+
+/*
+ * collate_error --
+ *	Handle errors in the collator in a standard way.
+ */
+static void
+collate_error(int ret, const char *description)
+{
+	fprintf(stderr, "revint_collator error: %s: %s\n",
+	    wiredtiger_strerror(ret), description);
+	/*
+	 * For errors, we call abort. Since this collator is used in testing
+	 * WiredTiger, we want it to immediately fail hard. A product-ready
+	 * version of this function would not abort.
+	 */
+	abort();
+}
+
+/*
+ * collate_revint --
+ *	WiredTiger reverse integer collation, used for tests.
+ */
+static int
+collate_revint(WT_COLLATOR *collator,
+    WT_SESSION *session, const WT_ITEM *k1, const WT_ITEM *k2, int *cmp)
+{
+	WT_PACK_STREAM *s1, *s2;
+	int ret;
+	int64_t i1, i2, p1, p2;
+
+	(void)collator;					/* Unused */
+	(void)session;
+
+	s1 = NULL;
+	s2 = NULL;
+
+	/*
+	 * All indices using this collator have an integer key, and the
+	 * primary key is also an integer. A collator is passed the
+	 * concatenation of index key and primary key (when available),
+	 * hence we unpack using "ii".
+	 */
+	if ((ret = wiredtiger_unpack_start(session, "ii",
+	    k1->data, k1->size, &s1)) != 0 || 
+	    (ret = wiredtiger_unpack_start(session, "ii",
+	    k2->data, k2->size, &s2)) != 0)
+		collate_error(ret, "unpack start");
+		/* does not return */
+
+	if ((ret = wiredtiger_unpack_int(s1, &i1)) != 0)
+		collate_error(ret, "unpack index key 1");
+	if ((ret = wiredtiger_unpack_int(s2, &i2)) != 0)
+		collate_error(ret, "unpack index key 2");
+
+	/* sorting is reversed */
+	if (i1 < i2)
+		*cmp = 1;
+	else if (i1 > i2)
+		*cmp = -1;
+	else {
+		/*
+		 * Compare primary keys next.
+		 *
+		 * Allow failures here.  A collator may be called with an
+		 * item that includes a index key and no primary key.  Among
+		 * items having the same index key, an item with no primary
+		 * key should sort before an item with a primary key. The
+		 * reason is that if the application calls WT_CURSOR::search
+		 * on a index key for which there are more than one value,
+		 * the search key will not yet have a primary key.  We want
+		 * to position the cursor at the 'first' matching index key
+		 * so that repeated calls to WT_CURSOR::next will see them
+		 * all.
+		 *
+		 * To keep this code simple, we do keep secondary sort of
+		 * primary keys in forward (not reversed) order.
+		 */
+		if ((ret = wiredtiger_unpack_int(s1, &p1)) != 0) {
+			if (ret == ENOMEM)
+				p1 = INT64_MIN; /* sort this first */
+			else
+				collate_error(ret, "unpack primary key 1");
+		}
+		if ((ret = wiredtiger_unpack_int(s2, &p2)) != 0) {
+			if (ret == ENOMEM)
+				p2 = INT64_MIN; /* sort this first */
+			else
+				collate_error(ret, "unpack primary key 2");
+		}
+		
+		/* sorting is not reversed here */
+		if (p1 < p2)
+			*cmp = -1;
+		else if (p1 > p2)
+			*cmp = 1;
+		else
+			*cmp = 0; /* index key and primary key are same */
+	}
+	if ((ret = wiredtiger_pack_close(s1, NULL)) != 0 ||
+	    (ret = wiredtiger_pack_close(s2, NULL)) != 0)
+		collate_error(ret, "unpack close");
+
+	return (0);
+}
+
+static WT_COLLATOR revint_collator = { collate_revint, NULL, NULL };
+
+/*
+ * wiredtiger_extension_init --
+ *	WiredTiger revint collation extension.
+ */
+int
+wiredtiger_extension_init(WT_CONNECTION *connection, WT_CONFIG_ARG *config)
+{
+	(void)config;				/* Unused parameters */
+
+	return (connection->add_collator(
+	    connection, "revint", &revint_collator, NULL));
+}