Add a test for stable sort

tests/c-tests/stable_sort.c

@@ -0,0 +1,86 @@
+
+#include <stdio.h>
+#include <assert.h>
+
+#include <traildb.h>
+#include <tdb_io.h>
+
+#include "tdb_test.h"
+
+struct event{
+    uint32_t time;
+    char value[1];
+};
+
+static void basic_sort(const char *root)
+{
+    static uint8_t uuid[16];
+    char path[TDB_MAX_PATH_SIZE];
+    const char *fields[] = {"f1"};
+    const uint64_t lengths[] = {1};
+    char prev;
+    uint64_t len, tstamp, i;
+
+    struct event EVENTS[] = {
+        {40,  "i" },
+        {3,   "a" },
+        {20,  "e" },
+        {41,  "m" },
+        {10,  "c" },
+        {40,  "j" },
+        {10,  "d" },
+        {20,  "f" },
+        {41,  "n" },
+        {41,  "o" },
+        {30,  "g" },
+        {5,   "b" },
+        {30,  "h" },
+        {40,  "k" },
+        {40,  "l" },
+    };
+    tdb_path(path, "%s.%u", root, 1);
+    tdb_cons* c = tdb_cons_init();
+    test_cons_settings(c);
+    assert(tdb_cons_open(c, path, fields, 1) == 0);
+
+    for (i = 0; i < sizeof(EVENTS)/sizeof(struct event); i++){
+        const char *values[] = {EVENTS[i].value};
+        assert(tdb_cons_add(c,
+                            uuid,
+                            EVENTS[i].time,
+                            values,
+                            lengths) == 0);
+    }
+
+    assert(tdb_cons_finalize(c) == 0);
+
+    tdb* db = tdb_init();
+    assert(tdb_open(db, path) == 0);
+    tdb_cursor *cursor = tdb_cursor_new(db);
+    assert(tdb_lexicon_size(db, 1) == 16);
+    assert(tdb_num_trails(db) == 1);
+    assert(tdb_get_trail(cursor, 0) == 0);
+    tstamp = 0;
+    prev = 0;
+    /* we expect a sequence
+        (5, a), (10, b), (10, c), ....
+       i.e. both timestamaps and values are monotonically increasing,
+       which we check below
+    */
+    const tdb_event *event;
+    while ((event = tdb_cursor_next(cursor))){
+        assert(tstamp <= event->timestamp);
+        tstamp = event->timestamp;
+        char c = tdb_get_item_value(db, event->items[0], &len)[0];
+        assert(prev < c);
+        prev = c;
+    }
+
+    tdb_close(db);
+}
+
+
+int main(int argc, char** argv)
+{
+    basic_sort(getenv("TDB_TMP_DIR"));
+}