Refs Tokutek/ft-index#46 cleaned up serialization, upped version to 26

ft/bndata.cc

@@ -125,7 +125,7 @@ void bn_data::remove_key(uint32_t keylen) {
 void bn_data::initialize_from_separate_keys_and_vals(uint32_t num_entries, struct rbuf *rb, uint32_t data_size, uint32_t version UU(),
                                                      uint32_t key_data_size, uint32_t val_data_size, bool all_keys_same_length,
                                                      uint32_t fixed_klpair_length) {
-    paranoid_invariant(version >= FT_LAYOUT_VERSION_25);  // Support was added @25
+    paranoid_invariant(version >= FT_LAYOUT_VERSION_26);  // Support was added @26
     uint32_t ndone_before = rb->ndone;
     init_zero();
     invariant(all_keys_same_length);  // Until otherwise supported.
@@ -152,6 +152,44 @@ void bn_data::initialize_from_separate_keys_and_vals(uint32_t num_entries, struc
     invariant(rb->ndone - ndone_before == data_size);
 }
 
+static int
+wbufwriteleafentry(const void* key, const uint32_t keylen, const LEAFENTRY &le, const uint32_t UU(idx), struct wbuf * const wb) {
+    // need to pack the leafentry as it was in versions
+    // where the key was integrated into it (< 26)
+    uint32_t begin_spot UU() = wb->ndone;
+    uint32_t le_disk_size = leafentry_disksize(le);
+    wbuf_nocrc_uint8_t(wb, le->type);
+    wbuf_nocrc_uint32_t(wb, keylen);
+    if (le->type == LE_CLEAN) {
+        wbuf_nocrc_uint32_t(wb, le->u.clean.vallen);
+        wbuf_nocrc_literal_bytes(wb, key, keylen);
+        wbuf_nocrc_literal_bytes(wb, le->u.clean.val, le->u.clean.vallen);
+    }
+    else {
+        paranoid_invariant(le->type == LE_MVCC);
+        wbuf_nocrc_uint32_t(wb, le->u.mvcc.num_cxrs);
+        wbuf_nocrc_uint8_t(wb, le->u.mvcc.num_pxrs);
+        wbuf_nocrc_literal_bytes(wb, key, keylen);
+        wbuf_nocrc_literal_bytes(wb, le->u.mvcc.xrs, le_disk_size - (1 + 4 + 1));
+    }
+    uint32_t end_spot UU() = wb->ndone;
+    paranoid_invariant((end_spot - begin_spot) == keylen + sizeof(keylen) + le_disk_size);
+    return 0;
+}
+
+void bn_data::serialize_to_wbuf(struct wbuf *const wb) {
+    prepare_to_serialize();
+    serialize_header(wb);
+    if (m_buffer.value_length_is_fixed()) {
+        serialize_rest(wb);
+    } else {
+        //
+        // iterate over leafentries and place them into the buffer
+        //
+        dmt_iterate<struct wbuf, wbufwriteleafentry>(wb);
+    }
+}
+
 // If we have fixed-length keys, we prepare the dmt and mempool.
 // The mempool is prepared by removing any fragmented space and ordering leafentries in the same order as their keys.
 void bn_data::prepare_to_serialize(void) {
@@ -188,40 +226,36 @@ void bn_data::serialize_rest(struct wbuf *wb) const {
     wbuf_nocrc_literal_bytes(wb, toku_mempool_get_base(&m_buffer_mempool), val_data_size);
 }
 
-// No optimized (de)serialize method implemented (yet?) for non-fixed length keys.
-bool bn_data::need_to_serialize_each_leafentry_with_key(void) const {
-    return !m_buffer.value_length_is_fixed();
-}
-
 // Deserialize from rbuf
 void bn_data::deserialize_from_rbuf(uint32_t num_entries, struct rbuf *rb, uint32_t data_size, uint32_t version) {
-    uint32_t key_data_size = data_size;  // overallocate if < version 25 (best guess that is guaranteed not too small)
-    uint32_t val_data_size = data_size;  // overallocate if < version 25 (best guess that is guaranteed not too small)
+    uint32_t key_data_size = data_size;  // overallocate if < version 26 (best guess that is guaranteed not too small)
+    uint32_t val_data_size = data_size;  // overallocate if < version 26 (best guess that is guaranteed not too small)
 
     bool all_keys_same_length = false;
     bool keys_vals_separate = false;
     uint32_t fixed_klpair_length = 0;
 
-    // In version 24 and older there is no header.  Skip reading header for old version.
-    if (version >= FT_LAYOUT_VERSION_25) {
+    // In version 25 and older there is no header.  Skip reading header for old version.
+    if (version >= FT_LAYOUT_VERSION_26) {
         uint32_t ndone_before = rb->ndone;
         key_data_size = rbuf_int(rb);
         val_data_size = rbuf_int(rb);
         fixed_klpair_length = rbuf_int(rb);  // 0 if !all_keys_same_length
         all_keys_same_length = rbuf_char(rb);
         keys_vals_separate = rbuf_char(rb);
-        invariant(all_keys_same_length == keys_vals_separate);  // Until we support this
+        invariant(all_keys_same_length == keys_vals_separate);  // Until we support otherwise
         uint32_t header_size = rb->ndone - ndone_before;
         data_size -= header_size;
         invariant(header_size == HEADER_LENGTH);
         if (keys_vals_separate) {
+            invariant(fixed_klpair_length >= sizeof(klpair_struct));
             initialize_from_separate_keys_and_vals(num_entries, rb, data_size, version,
                                                    key_data_size, val_data_size, all_keys_same_length,
                                                    fixed_klpair_length);
             return;
         }
     }
-    // Version >= 25 and version 24 deserialization are now identical except that <= 24 might allocate too much memory.
+    // Version >= 26 and version 25 deserialization are now identical except that <= 25 might allocate too much memory.
     bytevec bytes;
     rbuf_literal_bytes(rb, &bytes, data_size);
     const unsigned char *CAST_FROM_VOIDP(buf, bytes);
@@ -232,6 +266,7 @@ void bn_data::deserialize_from_rbuf(uint32_t num_entries, struct rbuf *rb, uint3
     klpair_dmt_t::builder dmt_builder;
     dmt_builder.create(num_entries, key_data_size);
 
+    // TODO(leif): clean this up (#149)
     unsigned char *newmem = nullptr;
     // add same wiggle room that toku_mempool_construct would, 25% extra
     uint32_t allocated_bytes_vals = val_data_size + val_data_size/4;
@@ -306,25 +341,13 @@ void bn_data::deserialize_from_rbuf(uint32_t num_entries, struct rbuf *rb, uint3
     toku_mempool_init(&m_buffer_mempool, newmem, (size_t)(curr_dest_pos - newmem), allocated_bytes_vals);
 
     paranoid_invariant(get_disk_size() == data_size);
-    // Versions older than 25 might have allocated too much memory.  Try to shrink the mempool now that we
+    // Versions older than 26 might have allocated too much memory.  Try to shrink the mempool now that we
     // know how much memory we need.
-    if (version < FT_LAYOUT_VERSION_25) {
-        //Maybe shrink mempool.  Unnecessary after version 25
-        size_t used = toku_mempool_get_used_space(&m_buffer_mempool);
-        size_t max_allowed = used + used / 4;
-        size_t allocated = toku_mempool_get_size(&m_buffer_mempool);
-        size_t footprint = toku_mempool_footprint(&m_buffer_mempool);
-        if (allocated > max_allowed && footprint > max_allowed) {
-            // Reallocate smaller mempool to save memory
-            invariant_zero(toku_mempool_get_frag_size(&m_buffer_mempool));
-            struct mempool new_mp;
-            toku_mempool_construct(&new_mp, used);
-            void * newbase = toku_mempool_malloc(&new_mp, used, 1);
-            invariant_notnull(newbase);
-            memcpy(newbase, toku_mempool_get_base(&m_buffer_mempool), used);
-            toku_mempool_destroy(&m_buffer_mempool);
-            m_buffer_mempool = new_mp;
-        }
+    if (version < FT_LAYOUT_VERSION_26) {
+        // Unnecessary after version 26
+        // Reallocate smaller mempool to save memory
+        invariant_zero(toku_mempool_get_frag_size(&m_buffer_mempool));
+        toku_mempool_realloc_larger(&m_buffer_mempool, toku_mempool_get_used_space(&m_buffer_mempool));
     }
 }
 
@@ -370,7 +393,7 @@ static int move_it (const uint32_t, klpair_struct *klpair, const uint32_t idx UU
     return 0;
 }
 
-// Compress things, and grow the mempool if needed.
+// Compress things, and grow or shrink the mempool if needed.
 // May (always if force_compress) have a side effect of putting contents of mempool in sorted order.
 void bn_data::dmt_compress_kvspace(size_t added_size, void **maybe_free, bool force_compress) {
     uint32_t total_size_needed = toku_mempool_get_used_space(&m_buffer_mempool) + added_size;

ft/bndata.h

@@ -316,6 +316,8 @@ class bn_data {
     // Gets a leafentry given a klpair from this basement node.
     LEAFENTRY get_le_from_klpair(const klpair_struct *klpair) const;
 
+    void serialize_to_wbuf(struct wbuf *const wb);
+
     // Prepares this basement node for serialization.
     // Must be called before serializing this basement node.
     // Between calling prepare_to_serialize and actually serializing, the basement node may not be modified
@@ -332,11 +334,6 @@ class bn_data {
     // Currently only supported when all keys are fixed-length.
     void serialize_rest(struct wbuf *wb) const;
 
-    // Returns true if we must use the old (version 24) serialization method for this basement node
-    // Requires prepare_to_serialize() to have been called first.
-    // In other words, the bndata does not know how to serialize the keys and leafentries.
-    bool need_to_serialize_each_leafentry_with_key(void) const;
-
     static const uint32_t HEADER_LENGTH = 0
         + sizeof(uint32_t) // key_data_size
         + sizeof(uint32_t) // val_data_size

ft/ft-serialize.cc

@@ -462,6 +462,7 @@ serialize_ft_min_size (uint32_t version) {
     size_t size = 0;
 
     switch(version) {
+    case FT_LAYOUT_VERSION_26:
     case FT_LAYOUT_VERSION_25:
     case FT_LAYOUT_VERSION_24:
     case FT_LAYOUT_VERSION_23:

ft/ft_layout_version.h

@@ -118,7 +118,8 @@ enum ft_layout_version_e {
     FT_LAYOUT_VERSION_22 = 22, // Ming: Add oldest known referenced xid to each ftnode, for better garbage collection
     FT_LAYOUT_VERSION_23 = 23, // Ming: Fix upgrade path #5902
     FT_LAYOUT_VERSION_24 = 24, // Riddler: change logentries that log transactions to store TXNID_PAIRs instead of TXNIDs
-    FT_LAYOUT_VERSION_25 = 25, // SecretSquirrel: ROLLBACK_LOG_NODES (on disk and in memory) now just use blocknum (instead of blocknum + hash) to point to other log nodes.  same for xstillopen log entry, basements store key/vals separately on disk
+    FT_LAYOUT_VERSION_25 = 25, // SecretSquirrel: ROLLBACK_LOG_NODES (on disk and in memory) now just use blocknum (instead of blocknum + hash) to point to other log nodes.  same for xstillopen log entry
+    FT_LAYOUT_VERSION_26 = 26, // Hojo: basements store key/vals separately on disk for fixed klpair length BNs
     FT_NEXT_VERSION,           // the version after the current version
     FT_LAYOUT_VERSION   = FT_NEXT_VERSION-1, // A hack so I don't have to change this line.
     FT_LAYOUT_MIN_SUPPORTED_VERSION = FT_LAYOUT_VERSION_13, // Minimum version supported

ft/ft_node-serialize.cc

@@ -284,31 +284,6 @@ serialize_node_header(FTNODE node, FTNODE_DISK_DATA ndd, struct wbuf *wbuf) {
     invariant(wbuf->ndone == wbuf->size);
 }
 
-static int
-wbufwriteleafentry(const void* key, const uint32_t keylen, const LEAFENTRY &le, const uint32_t UU(idx), struct wbuf * const wb) {
-    // need to pack the leafentry as it was in versions
-    // where the key was integrated into it
-    uint32_t begin_spot UU() = wb->ndone;
-    uint32_t le_disk_size = leafentry_disksize(le);
-    wbuf_nocrc_uint8_t(wb, le->type);
-    wbuf_nocrc_uint32_t(wb, keylen);
-    if (le->type == LE_CLEAN) {
-        wbuf_nocrc_uint32_t(wb, le->u.clean.vallen);
-        wbuf_nocrc_literal_bytes(wb, key, keylen);
-        wbuf_nocrc_literal_bytes(wb, le->u.clean.val, le->u.clean.vallen);
-    }
-    else {
-        paranoid_invariant(le->type == LE_MVCC);
-        wbuf_nocrc_uint32_t(wb, le->u.mvcc.num_cxrs);
-        wbuf_nocrc_uint8_t(wb, le->u.mvcc.num_pxrs);
-        wbuf_nocrc_literal_bytes(wb, key, keylen);
-        wbuf_nocrc_literal_bytes(wb, le->u.mvcc.xrs, le_disk_size - (1 + 4 + 1));
-    }
-    uint32_t end_spot UU() = wb->ndone;
-    paranoid_invariant((end_spot - begin_spot) == keylen + sizeof(keylen) + le_disk_size);
-    return 0;
-}
-
 static uint32_t 
 serialize_ftnode_partition_size (FTNODE node, int i)
 {
@@ -380,16 +355,7 @@ serialize_ftnode_partition(FTNODE node, int i, struct sub_block *sb) {
         wbuf_nocrc_char(&wb, ch);
         wbuf_nocrc_uint(&wb, bd->dmt_size());
 
-        bd->prepare_to_serialize();
-        bd->serialize_header(&wb);
-        if (bd->need_to_serialize_each_leafentry_with_key()) {
-            //
-            // iterate over leafentries and place them into the buffer
-            //
-            bd->dmt_iterate<struct wbuf, wbufwriteleafentry>(&wb);
-        } else {
-            bd->serialize_rest(&wb);
-        }
+        bd->serialize_to_wbuf(&wb);
     }
     uint32_t end_to_end_checksum = x1764_memory(sb->uncompressed_ptr, wbuf_get_woffset(&wb));
     wbuf_nocrc_int(&wb, end_to_end_checksum);

util/dmt.cc

@@ -1240,7 +1240,7 @@ void dmt<dmtdata_t, dmtdataout_t, dmtwriter_t>::builder::build(dmt<dmtdata_t, dm
     // When we know the elements are fixed-length, we use the better dmt constructor.
     // In practice, as of Jan 2014, we use the builder in two cases:
     //  - When we know the elements are not fixed-length.
-    //  - During upgrade of a pre version 25 basement node.
+    //  - During upgrade of a pre version 26 basement node.
     // During upgrade, we will probably wildly overallocate because we don't account for the values that aren't stored in the dmt, so here we want to shrink the mempool.
     // When we know the elements are not fixed-length, we still know how much memory they occupy in total, modulo alignment, so we want to allow for mempool overhead and worst-case alignment overhead, and not shrink the mempool.
     const size_t max_allowed = used + (ALIGNMENT-1) * this->temp.size();