try to implement cursor.count, cursor.next_nodup, and cursor.prev_nodup on top...

try to implement cursor.count, cursor.next_nodup, and cursor.prev_nodup on top of the more basic cursor operations.  addresses #258 #259

git-svn-id: file:///svn/tokudb@1573 c7de825b-a66e-492c-adef-691d508d4ae1

cxx/tests/test_cursor_count.cpp

+#include <stdlib.h>
+#include <arpa/inet.h>
+#include <assert.h>
+#include <db_cxx.h>
+
+#ifndef DB_YESOVERWRITE
+#define BDB 1
+#define DB_YESOVERWRITE 0
+#else
+#define TDB 1
+typedef u_int32_t db_recno_t;
+#endif
+
+int keyeq(Dbt *a, Dbt *b) {
+    if (a->get_size() != b->get_size()) return 0;
+    return memcmp(a->get_data(), b->get_data(), a->get_size()) == 0;
+}
+
+void load(Db *db, int n) {
+    printf("load\n");
+    int i;
+    for (i=0; i<n; i++) {
+        if (i == n/2) continue;
+        int k = htonl(i);
+        Dbt key(&k, sizeof k);
+        int v = i;
+        Dbt val(&v, sizeof v);
+        int r = db->put(0, &key, &val, DB_YESOVERWRITE); assert(r == 0);
+    }
+
+    for (i=0; i<n; i++) {
+        int k = htonl(n/2);
+        int v = i;
+        Dbt key(&k, sizeof k);
+        Dbt val(&v, sizeof v);
+        int r = db->put(0, &key, &val, DB_YESOVERWRITE); assert(r == 0);
+    }
+}
+
+db_recno_t my_cursor_count(Db *db, Dbc *cursor) {
+    int r;
+    Dbt key; key.set_flags(DB_DBT_REALLOC);
+    Dbt val; val.set_flags(DB_DBT_REALLOC);
+    r = cursor->get(&key, &val, DB_CURRENT); assert(r == 0);
+    
+    Dbc *count_cursor;
+    r = db->cursor(0, &count_cursor, 0); assert(r == 0);
+    r = count_cursor->get(&key, &val, DB_SET); assert(r == 0);
+    int nmatch;
+    Dbt nkey, nval;
+    for (nmatch=1; ; nmatch++) {
+        nkey.set_flags(DB_DBT_REALLOC);
+        nval.set_flags(DB_DBT_REALLOC);
+        r = count_cursor->get(&nkey, &nval, DB_NEXT);
+        if (r != 0) break;
+        if (!keyeq(&key, &nkey)) break;
+    }
+    if (nkey.get_data()) free(nkey.get_data());
+    if (nval.get_data()) free(nval.get_data());
+    if (key.get_data()) free(key.get_data());
+    if (val.get_data()) free(val.get_data());
+    r = count_cursor->close(); assert(r == 0);
+    return nmatch;
+}
+
+void walk(Db *db, int n) {
+    printf("walk\n");
+    Dbc *cursor;
+    int r = db->cursor(0, &cursor, 0); assert(r == 0);
+    int i;
+    Dbt key, val;
+    for (i=0; ; i++) {
+        key.set_flags(DB_DBT_REALLOC);
+        val.set_flags(DB_DBT_REALLOC);
+        r = cursor->get(&key, &val, DB_NEXT);
+        if (r != 0) break;
+        int k;
+        assert(key.get_size() == sizeof k);
+        memcpy(&k, key.get_data(), key.get_size());
+        k = htonl(k);
+        int v;
+        assert(val.get_size() == sizeof v);
+        memcpy(&v, val.get_data(), val.get_size());
+        db_recno_t nmatch;
+#if BDB
+        r = cursor->count(&nmatch, 0);
+        printf("%d %d %d\n", k, v, nmatch);
+        assert(my_cursor_count(db, cursor) == nmatch);
+#else
+        nmatch = my_cursor_count(db, cursor);
+        printf("%d %d %d\n", k, v, nmatch);
+        if (k == n/2) assert(nmatch == (db_recno_t) n); else assert(nmatch == 1);
+#endif      
+    }
+    free(key.get_data());
+    free(val.get_data());
+    r = cursor->close(); assert(r == 0);
+}
+
+int my_next_nodup(Dbc *cursor, Dbt *key, Dbt *val) {
+    int r;
+    Dbt currentkey; currentkey.set_flags(DB_DBT_REALLOC);
+    Dbt currentval; currentval.set_flags(DB_DBT_REALLOC);
+    r = cursor->get(&currentkey, &currentval, DB_CURRENT); assert(r == 0);
+    Dbt nkey; nkey.set_flags(DB_DBT_REALLOC);
+    Dbt nval; nval.set_flags(DB_DBT_REALLOC);
+    for (;;) {
+        r = cursor->get(&nkey, &nval, DB_NEXT);
+        if (r != 0) break;
+        if (!keyeq(&currentkey, &nkey)) break;
+    }
+    if (nkey.get_data()) free(nkey.get_data());
+    if (nval.get_data()) free(nval.get_data());
+    if (currentkey.get_data()) free(currentkey.get_data());
+    if (currentval.get_data()) free(currentval.get_data());
+    if (r == 0) r = cursor->get(key, val, DB_CURRENT);
+    return r;
+}
+
+int my_prev_nodup(Dbc *cursor, Dbt *key, Dbt *val) {
+    int r;
+    Dbt currentkey; currentkey.set_flags(DB_DBT_REALLOC);
+    Dbt currentval; currentval.set_flags(DB_DBT_REALLOC);
+    r = cursor->get(&currentkey, &currentval, DB_CURRENT); assert(r == 0);
+    Dbt nkey; nkey.set_flags(DB_DBT_REALLOC);
+    Dbt nval; nval.set_flags(DB_DBT_REALLOC);
+    for (;;) {
+        r = cursor->get(&nkey, &nval, DB_PREV);
+        if (r != 0) break;
+        if (!keyeq(&currentkey, &nkey)) break;
+    }
+    if (nkey.get_data()) free(nkey.get_data());
+    if (nval.get_data()) free(nval.get_data());
+    if (currentkey.get_data()) free(currentkey.get_data());
+    if (currentval.get_data()) free(currentval.get_data());
+    if (r == 0) r = cursor->get(key, val, DB_CURRENT);
+    return r;
+}
+
+void test_next_nodup(Db *db, int n) {
+    printf("test_next_nodup\n");
+    int r;
+    Dbc *cursor;
+    r = db->cursor(0, &cursor, 0); assert(r == 0);
+    Dbt key; key.set_flags(DB_DBT_REALLOC);
+    Dbt val; val.set_flags(DB_DBT_REALLOC);
+    r = cursor->get(&key, &val, DB_FIRST); assert(r == 0);
+    printf("%d %d\n", htonl(*(int*)key.get_data()), *(int*)val.get_data());
+    for (;;) {
+        r = my_next_nodup(cursor, &key, &val);
+        if (r != 0) break;
+        printf("%d %d\n", htonl(*(int*)key.get_data()), *(int*)val.get_data());
+    }
+    if (key.get_data()) free(key.get_data());
+    if (val.get_data()) free(val.get_data());
+    r = cursor->close(); assert(r == 0);
+}
+
+int main() {
+    int r;
+
+    Db db(0, DB_CXX_NO_EXCEPTIONS);
+    r = db.set_flags(DB_DUP + DB_DUPSORT); assert(r == 0);
+    r = db.open(0, "test.db", 0, DB_BTREE, DB_CREATE, 0777); assert(r == 0);
+    
+    load(&db, 10);
+    walk(&db, 10);
+    test_next_nodup(&db, 10);
+
+    return 0;
+}