implement DB_CURRENT_BINDING, an operation that returns the current cursor kv...

implement DB_CURRENT_BINDING, an operation that returns the current cursor kv binding even if deleted.  closes #274

git-svn-id: file:///svn/tokudb@2063 c7de825b-a66e-492c-adef-691d508d4ae1

buildheader/db.h_4_1

@@ -89,6 +89,7 @@ typedef enum {
 #define DB_PREV_NODUP 28
 #define DB_SET 30
 #define DB_SET_RANGE 32
+#define DB_CURRENT_BINDING 253
 #define DB_RMW 1073741824
 #define DB_DBT_APPMALLOC 1
 #define DB_TXN_WRITE_NOSYNC 524288

buildheader/db.h_4_3

@@ -90,6 +90,7 @@ typedef enum {
 #define DB_PREV_NODUP 26
 #define DB_SET 28
 #define DB_SET_RANGE 30
+#define DB_CURRENT_BINDING 253
 #define DB_RMW 536870912
 #define DB_DBT_APPMALLOC 1
 #define DB_LOG_AUTOREMOVE 65536

buildheader/db.h_4_4

@@ -90,6 +90,7 @@ typedef enum {
 #define DB_PREV_NODUP 26
 #define DB_SET 28
 #define DB_SET_RANGE 30
+#define DB_CURRENT_BINDING 253
 #define DB_RMW 536870912
 #define DB_DBT_APPMALLOC 1
 #define DB_LOG_AUTOREMOVE 262144

buildheader/db.h_4_5

@@ -90,6 +90,7 @@ typedef enum {
 #define DB_PREV_NODUP 24
 #define DB_SET 25
 #define DB_SET_RANGE 27
+#define DB_CURRENT_BINDING 253
 #define DB_RMW 1073741824
 #define DB_DBT_APPMALLOC 1
 #define DB_LOG_AUTOREMOVE 524288

buildheader/db.h_4_6

@@ -91,6 +91,7 @@ typedef enum {
 #define DB_PREV_NODUP 25
 #define DB_SET 26
 #define DB_SET_RANGE 27
+#define DB_CURRENT_BINDING 253
 #define DB_RMW 1073741824
 #define DB_DBT_APPMALLOC 1
 #define DB_DBT_MULTIPLE 16

buildheader/make_db_h.c

@@ -101,6 +101,7 @@ void print_defines (void) {
     dodefine(DB_PREV_NODUP);
     dodefine(DB_SET);
     dodefine(DB_SET_RANGE);
+    printf("#define DB_CURRENT_BINDING 253\n"); // private tokudb
     dodefine(DB_RMW);
 
     dodefine(DB_DBT_APPMALLOC);

include/db.h

@@ -90,6 +90,7 @@ typedef enum {
 #define DB_PREV_NODUP 26
 #define DB_SET 28
 #define DB_SET_RANGE 30
+#define DB_CURRENT_BINDING 253
 #define DB_RMW 536870912
 #define DB_DBT_APPMALLOC 1
 #define DB_LOG_AUTOREMOVE 262144

newbrt/brt-test.c

@@ -2577,7 +2577,7 @@ static void test_new_brt_cursor_current(int n, int dup_mode) {
         memcpy(&vv, val.data, val.size);
         assert(vv == (int) htonl(i));
 
-        r = toku_brt_cursor_get(cursor, &key, &val, DB_CURRENT+256, null_txn); assert(r == 0);
+        r = toku_brt_cursor_get(cursor, &key, &val, DB_CURRENT_BINDING, null_txn); assert(r == 0);
         assert(key.size == sizeof kk);
         memcpy(&kk, key.data, key.size);
         assert(kk == (int) htonl(i));
@@ -2589,7 +2589,7 @@ static void test_new_brt_cursor_current(int n, int dup_mode) {
 
         r = toku_brt_cursor_get(cursor, &key, &val, DB_CURRENT, null_txn); assert(r == DB_KEYEMPTY);
 
-        r = toku_brt_cursor_get(cursor, &key, &val, DB_CURRENT+256, null_txn); assert(r == 0);
+        r = toku_brt_cursor_get(cursor, &key, &val, DB_CURRENT_BINDING, null_txn); assert(r == 0);
         assert(key.size == sizeof kk);
         memcpy(&kk, key.data, key.size);
         assert(kk == (int) htonl(i));

newbrt/brt.c

@@ -2053,10 +2053,10 @@ static int brt_cursor_compare_set(brt_search_t *search, DBT *x, DBT *y) {
     return compare_kv_xy(brt, search->k, search->v, x, y) <= 0; /* return min xy: kv <= xy */
 }
 
-static int brt_cursor_current(BRT_CURSOR cursor, int get_flags, DBT *outkey, DBT *outval, TOKUTXN txn) {
+static int brt_cursor_current(BRT_CURSOR cursor, int op, DBT *outkey, DBT *outval, TOKUTXN txn) {
     if (brt_cursor_not_set(cursor))
         return EINVAL;
-    if ((get_flags & 256) == 0) {
+    if (op == DB_CURRENT) {
         DBT newkey; toku_init_dbt(&newkey);
         DBT newval; toku_init_dbt(&newval);
 
@@ -2236,17 +2236,16 @@ static int brt_cursor_set_range(BRT_CURSOR cursor, DBT *key, DBT *outkey, DBT *o
 }
 
 int toku_brt_cursor_get (BRT_CURSOR cursor, DBT *key, DBT *val, int get_flags, TOKUTXN txn) {
-    assert(txn == 0);
-
     int r;
 
-    if ((get_flags & ~(DB_OPFLAGS_MASK+256)))
+    int op = get_flags & DB_OPFLAGS_MASK;
+    if (get_flags & ~DB_OPFLAGS_MASK) 
         return EINVAL;
 
-    switch (get_flags) {
+    switch (op) {
     case DB_CURRENT:
-    case DB_CURRENT+256:
-        r = brt_cursor_current(cursor, get_flags, key, val, txn);
+    case DB_CURRENT_BINDING:
+        r = brt_cursor_current(cursor, op, key, val, txn);
         break;
     case DB_FIRST:
         r = brt_cursor_first(cursor, key, val, txn);

src/ydb.c

@@ -1135,7 +1135,7 @@ static int toku_c_count(DBC *cursor, db_recno_t *count, u_int32_t flags) {
         r = EINVAL; goto finish;
     }
 
-    r = toku_c_get(cursor, &currentkey, &currentval, DB_CURRENT+256);
+    r = toku_c_get(cursor, &currentkey, &currentval, DB_CURRENT_BINDING);
     if (r != 0) goto finish;
     
     r = toku_db_cursor(cursor->dbp, 0, &count_cursor, 0);