Refs Tokutek/ft-index#46 Comments, minor renames, reworked...

Refs Tokutek/ft-index#46 Comments, minor renames, reworked bn_data::move_leafentries s.t. splits do not significantly increase memory usage of basement nodes and to be cleaner

ft/bndata.h

@@ -193,9 +193,11 @@ class bn_data {
     void verify_mempool(void);
 
     // size() of key dmt
+    // TODO(yoni): maybe rename to something like num_klpairs
     uint32_t dmt_size(void) const;
 
     // iterate() on key dmt (and associated leafentries)
+    // TODO(yoni): rename to iterate
     template<typename iterate_extra_t,
              int (*f)(const void * key, const uint32_t keylen, const LEAFENTRY &, const uint32_t, iterate_extra_t *const)>
     int dmt_iterate(iterate_extra_t *const iterate_extra) const {
@@ -203,6 +205,7 @@ class bn_data {
     }
 
     // iterate_on_range() on key dmt (and associated leafentries)
+    // TODO(yoni): rename to iterate_on_range
     template<typename iterate_extra_t,
              int (*f)(const void * key, const uint32_t keylen, const LEAFENTRY &, const uint32_t, iterate_extra_t *const)>
     int dmt_iterate_on_range(const uint32_t left, const uint32_t right, iterate_extra_t *const iterate_extra) const {
@@ -272,10 +275,7 @@ class bn_data {
     // Move leafentries (and associated key/keylens) from this basement node to dest_bd
     // Moves indexes [lbi-ube)
     __attribute__((__nonnull__))
-    void move_leafentries_to(bn_data* dest_bd,
-                              uint32_t lbi, //lower bound inclusive
-                              uint32_t ube //upper bound exclusive
-                              );
+    void split_klpairs(bn_data* dest_bd, uint32_t first_index_for_dest);
 
     // Destroy this basement node and free memory.
     void destroy(void);
@@ -321,6 +321,8 @@ class bn_data {
     // Between calling prepare_to_serialize and actually serializing, the basement node may not be modified
     void prepare_to_serialize(void);
 
+    //TODO(yoni): go to serialize_ftnode_partition and move prepare/header/etc (and wbufwriteleafentry) into here and add just one external function: serialize_to_wbuf()
+
     // Serialize the basement node header to a wbuf
     // Requires prepare_to_serialize() to have been called first.
     void serialize_header(struct wbuf *wb) const;
@@ -344,10 +346,10 @@ class bn_data {
         + 0;
 private:
 
-    // move_leafentry_extra should be a local class in move_leafentries_to, but
+    // split_klpairs_extra should be a local class in split_klpairs, but
     // the dmt template parameter for iterate needs linkage, so it has to be a
     // separate class, but we want it to be able to call e.g. add_key
-    friend class move_leafentry_extra;
+    friend class split_klpairs_extra;
 
     // Allocates space in the mempool.
     // If there is insufficient space, the mempool is enlarged and leafentries may be shuffled to reduce fragmentation.
@@ -364,7 +366,7 @@ class bn_data {
     void add_key(uint32_t keylen);
 
     // Note that multiple keys were added (for maintaining disk-size of this basement node)
-    void add_keys(uint32_t n_keys, uint32_t combined_keylen);
+    void add_keys(uint32_t n_keys, uint32_t combined_klpair_len);
 
     // Note that a key was removed (for maintaining disk-size of this basement node)
     void remove_key(uint32_t keylen);
@@ -375,7 +377,7 @@ class bn_data {
     friend class bndata_bugfix_test;
 
     // Get the serialized size of a klpair.
-    // As of Jan 14, 2014, serialized size of a klpair is independent of if this basement node has fixed-length keys.
+    // As of Jan 14, 2014, serialized size of a klpair is independent of whether this basement node has fixed-length keys.
     uint32_t klpair_disksize(const uint32_t klpair_len, const klpair_struct *klpair) const;
 
     // The disk/memory size of all keys.  (Note that the size of memory for the leafentries is maintained by m_buffer_mempool)
@@ -385,6 +387,6 @@ class bn_data {
     // all keys will be first followed by all leafentries (both in sorted order)
     void initialize_from_separate_keys_and_vals(uint32_t num_entries, struct rbuf *rb, uint32_t data_size, uint32_t version,
                                                 uint32_t key_data_size, uint32_t val_data_size, bool all_keys_same_length,
-                                                uint32_t fixed_key_length);
+                                                uint32_t fixed_klpair_length);
 };
 

ft/ft-flusher.cc

@@ -754,7 +754,8 @@ move_leafentries(
     )
 //Effect: move leafentries in the range [lbi, upe) from src_omt to newly created dest_omt
 {
-    src_bn->data_buffer.move_leafentries_to(&dest_bn->data_buffer, lbi, ube);
+    invariant(ube == src_bn->data_buffer.dmt_size());
+    src_bn->data_buffer.split_klpairs(&dest_bn->data_buffer, lbi);
 }
 
 static void ftnode_finalize_split(FTNODE node, FTNODE B, MSN max_msn_applied_to_node) {

ft/ft_node-serialize.cc

@@ -327,7 +327,7 @@ serialize_ftnode_partition_size (FTNODE node, int i)
     return result;
 }
 
-#define FTNODE_PARTITION_OMT_LEAVES 0xaa
+#define FTNODE_PARTITION_DMT_LEAVES 0xaa
 #define FTNODE_PARTITION_FIFO_MSG 0xbb
 
 static void
@@ -374,7 +374,7 @@ serialize_ftnode_partition(FTNODE node, int i, struct sub_block *sb) {
         serialize_nonleaf_childinfo(BNC(node, i), &wb);
     }
     else {
-        unsigned char ch = FTNODE_PARTITION_OMT_LEAVES;
+        unsigned char ch = FTNODE_PARTITION_DMT_LEAVES;
         bn_data* bd = BLB_DATA(node, i);
 
         wbuf_nocrc_char(&wb, ch);
@@ -1553,7 +1553,7 @@ deserialize_ftnode_partition(
         BP_WORKDONE(node, childnum) = 0;
     }
     else {
-        assert(ch == FTNODE_PARTITION_OMT_LEAVES);
+        assert(ch == FTNODE_PARTITION_DMT_LEAVES);
         BLB_SEQINSERT(node, childnum) = 0;
         uint32_t num_entries = rbuf_int(&rb);
         // we are now at the first byte of first leafentry

ft/ule.cc

@@ -927,7 +927,7 @@ le_pack(ULE ule, // data to be packed into new leafentry
         rval = 0;
         goto cleanup;
     }
-found_insert:;
+found_insert:
     memsize = le_memsize_from_ule(ule);
     LEAFENTRY new_leafentry;
     get_space_for_le(data_buffer, idx, keyp, keylen, old_le_size, memsize, &new_leafentry);

util/mempool.cc

@@ -183,6 +183,7 @@ size_t toku_mempool_get_size(const struct mempool *mp) {
     return mp->size;
 }
 
+// TODO(yoni): unify the toku_mempool_get*_size and toku_mempool_get*_space functions (use either size or space but not both)
 size_t toku_mempool_get_frag_size(const struct mempool *mp) {
     return mp->frag_size;
 }