FT-249 Move de/serialization code to the message buffer class itself,

further simplifying the logic that is contained in
ft/ft_node-serialize.cc

ft/ft_node-serialize.cc

@@ -341,41 +341,26 @@ wbuf_write_offset(const int32_t &offset, const uint32_t UU(idx), struct wbuf *co
     return 0;
 }
 
-static void
-serialize_child_buffer(NONLEAF_CHILDINFO bnc, struct wbuf *wb)
-{
+static void serialize_child_buffer(NONLEAF_CHILDINFO bnc, struct wbuf *wb) {
     unsigned char ch = FTNODE_PARTITION_MSG_BUFFER;
     wbuf_nocrc_char(wb, ch);
 
-    // serialize the message buffer, first the number of entries, then the elements
-    wbuf_nocrc_int(wb, toku_bnc_n_entries(bnc));
-    struct msg_serialize_fn {
-        struct wbuf *wb;
-        msg_serialize_fn(struct wbuf *w) : wb(w) { }
-        int operator()(FT_MSG msg, bool is_fresh) {
-            enum ft_msg_type type = (enum ft_msg_type) msg->type;
-            paranoid_invariant((int) type >= 0 && (int) type < 256);
-            wbuf_nocrc_char(wb, (unsigned char) type);
-            wbuf_nocrc_char(wb, (unsigned char) is_fresh);
-            wbuf_MSN(wb, msg->msn);
-            wbuf_nocrc_xids(wb, ft_msg_get_xids(msg));
-            wbuf_nocrc_bytes(wb, ft_msg_get_key(msg), ft_msg_get_keylen(msg));
-            wbuf_nocrc_bytes(wb, ft_msg_get_val(msg), ft_msg_get_vallen(msg));
-            return 0;
-        }
-    } serialize_fn(wb);
-    bnc->msg_buffer.iterate(serialize_fn);
+    // serialize the message buffer
+    bnc->msg_buffer.serialize_to_wbuf(wb);
 
+    // serialize the message trees (num entries, offsets array):
+    // first, verify their contents are consistent with the message buffer
     bnc_verify_message_trees(bnc);
 
-    // serialize the message trees (num entries, offsets array):
-    //    fresh, stale, broadcast
+    // fresh
     wbuf_nocrc_int(wb, bnc->fresh_message_tree.size());
     bnc->fresh_message_tree.iterate<struct wbuf, wbuf_write_offset>(wb);
 
+    // stale
     wbuf_nocrc_int(wb, bnc->stale_message_tree.size());
     bnc->stale_message_tree.iterate<struct wbuf, wbuf_write_offset>(wb);
 
+    // broadcast
     wbuf_nocrc_int(wb, bnc->broadcast_list.size());
     bnc->broadcast_list.iterate<struct wbuf, wbuf_write_offset>(wb);
 }
@@ -875,67 +860,23 @@ toku_serialize_ftnode_to (int fd, BLOCKNUM blocknum, FTNODE node, FTNODE_DISK_DA
 
 static void
 deserialize_child_buffer_v26(NONLEAF_CHILDINFO bnc, struct rbuf *rbuf, const toku::comparator &cmp) {
-    int n_in_this_buffer = rbuf_int(rbuf);
-    int32_t *fresh_offsets = nullptr, *stale_offsets = nullptr;
-    int32_t *broadcast_offsets = nullptr;
-    int nfresh = 0, nstale = 0;
-    int nbroadcast_offsets = 0;
+    int32_t nfresh = 0, nstale = 0, nbroadcast = 0;
+    int32_t *fresh_offsets, *stale_offsets, *broadcast_offsets;
 
     // Only sort buffers if we have a valid comparison function. In certain scenarios,
     // like deserialie_ft_versioned() or tokuftdump, we'll need to deserialize ftnodes
     // for simple inspection and don't actually require that the message buffers are
     // properly sorted. This is very ugly, but correct.
-    const bool sort_buffers = cmp.valid();
+    const bool sort = cmp.valid();
 
-    if (sort_buffers) {
-        XMALLOC_N(n_in_this_buffer, stale_offsets);
-        XMALLOC_N(n_in_this_buffer, fresh_offsets);
-        XMALLOC_N(n_in_this_buffer, broadcast_offsets);
-    }
+    // read in the message buffer
+    bnc->msg_buffer.deserialize_from_rbuf(rbuf,
+                                          sort ? &fresh_offsets : nullptr, &nfresh,
+                                          sort ? &stale_offsets : nullptr, &nstale,
+                                          sort ? &broadcast_offsets : nullptr, &nbroadcast);
 
-    bnc->msg_buffer.resize(rbuf->size + 64);
-    for (int i = 0; i < n_in_this_buffer; i++) {
-        bytevec key; ITEMLEN keylen;
-        bytevec val; ITEMLEN vallen;
-        // this is weird but it's necessary to pass icc and gcc together
-        unsigned char ctype = rbuf_char(rbuf);
-        enum ft_msg_type type = (enum ft_msg_type) ctype;
-        bool is_fresh = rbuf_char(rbuf);
-        MSN msn = rbuf_msn(rbuf);
-        XIDS xids;
-        xids_create_from_buffer(rbuf, &xids);
-        rbuf_bytes(rbuf, &key, &keylen); /* Returns a pointer into the rbuf. */
-        rbuf_bytes(rbuf, &val, &vallen);
-        int32_t *dest = nullptr;
-        if (sort_buffers) {
-            if (ft_msg_type_applies_once(type)) {
-                if (is_fresh) {
-                    dest = &fresh_offsets[nfresh];
-                    nfresh++;
-                } else {
-                    dest = &stale_offsets[nstale];
-                    nstale++;
-                }
-            } else if (ft_msg_type_applies_all(type) || ft_msg_type_does_nothing(type)) {
-                dest = &broadcast_offsets[nbroadcast_offsets];
-                nbroadcast_offsets++;
-            } else {
-                abort();
-            }
-        }
-
-        // TODO: Function to parse stuff out of an rbuf into an FT_MSG
-        DBT k, v;
-        FT_MSG_S msg = {
-            type, msn, xids,
-            .u = { .id = { toku_fill_dbt(&k, key, keylen), toku_fill_dbt(&v, val, vallen) } }
-        };
-        bnc->msg_buffer.enqueue(&msg, is_fresh, dest);
-        xids_destroy(&xids);
-    }
-    invariant(rbuf->ndone == rbuf->size);
-
-    if (sort_buffers) {
+    if (sort) {
+        int n_in_this_buffer = nfresh + nstale + nbroadcast;
         struct toku_msg_buffer_key_msn_cmp_extra extra(cmp, &bnc->msg_buffer);
         toku::sort<int32_t, const struct toku_msg_buffer_key_msn_cmp_extra, toku_msg_buffer_key_msn_cmp>::mergesort_r(fresh_offsets, nfresh, extra);
         bnc->fresh_message_tree.destroy();
@@ -944,66 +885,44 @@ deserialize_child_buffer_v26(NONLEAF_CHILDINFO bnc, struct rbuf *rbuf, const tok
         bnc->stale_message_tree.destroy();
         bnc->stale_message_tree.create_steal_sorted_array(&stale_offsets, nstale, n_in_this_buffer);
         bnc->broadcast_list.destroy();
-        bnc->broadcast_list.create_steal_sorted_array(&broadcast_offsets, nbroadcast_offsets, n_in_this_buffer);
+        bnc->broadcast_list.create_steal_sorted_array(&broadcast_offsets, nbroadcast, n_in_this_buffer);
     }
 }
 
-// effect: deserialize a single message from rbuf and enqueue the result into the given message buffer
-static void
-msg_buffer_deserialize_msg_from_rbuf(message_buffer *msg_buffer, struct rbuf *rbuf) {
-    bytevec key, val;
-    ITEMLEN keylen, vallen;
-    enum ft_msg_type type = (enum ft_msg_type) rbuf_char(rbuf);
-    bool is_fresh = rbuf_char(rbuf);
-    MSN msn = rbuf_msn(rbuf);
-    XIDS xids;
-    xids_create_from_buffer(rbuf, &xids);
-    rbuf_bytes(rbuf, &key, &keylen); /* Returns a pointer into the rbuf. */
-    rbuf_bytes(rbuf, &val, &vallen);
-    // TODO: Function to parse stuff out of an rbuf into an FT_MSG
-    DBT k, v;
-    FT_MSG_S msg = {
-        type, msn, xids,
-        .u = { .id = { toku_fill_dbt(&k, key, keylen), toku_fill_dbt(&v, val, vallen) } }
-    };
-    msg_buffer->enqueue(&msg, is_fresh, nullptr);
-    xids_destroy(&xids);
-}
-
 static void
 deserialize_child_buffer(NONLEAF_CHILDINFO bnc, struct rbuf *rbuf) {
-    int n_in_this_buffer = rbuf_int(rbuf);
-    int nfresh = 0, nstale = 0, nbroadcast_offsets = 0;
-    int32_t *XMALLOC_N(n_in_this_buffer, stale_offsets);
-    int32_t *XMALLOC_N(n_in_this_buffer, fresh_offsets);
-    int32_t *XMALLOC_N(n_in_this_buffer, broadcast_offsets);
-
-    bnc->msg_buffer.resize(rbuf->size + 64);
-    for (int i = 0; i < n_in_this_buffer; i++) {
-        msg_buffer_deserialize_msg_from_rbuf(&bnc->msg_buffer, rbuf);
-    }
+    // read in the message buffer
+    bnc->msg_buffer.deserialize_from_rbuf(rbuf,
+                                          nullptr, nullptr,  // fresh_offsets, nfresh,
+                                          nullptr, nullptr,  // stale_offsets, nstale,
+                                          nullptr, nullptr); // broadcast_offsets, nbroadcast
 
     // read in each message tree (fresh, stale, broadcast)
-    nfresh = rbuf_int(rbuf);
+    int32_t nfresh = rbuf_int(rbuf);
+    int32_t *XMALLOC_N(nfresh, fresh_offsets);
     for (int i = 0; i < nfresh; i++) {
         fresh_offsets[i] = rbuf_int(rbuf);
     }
-    nstale = rbuf_int(rbuf);
+
+    int32_t nstale = rbuf_int(rbuf);
+    int32_t *XMALLOC_N(nstale, stale_offsets);
     for (int i = 0; i < nstale; i++) {
         stale_offsets[i] = rbuf_int(rbuf);
     }
-    nbroadcast_offsets = rbuf_int(rbuf);
-    for (int i = 0; i < nbroadcast_offsets; i++) {
+
+    int32_t nbroadcast = rbuf_int(rbuf);
+    int32_t *XMALLOC_N(nbroadcast, broadcast_offsets);
+    for (int i = 0; i < nbroadcast; i++) {
         broadcast_offsets[i] = rbuf_int(rbuf);
     }
 
     // build OMTs out of each offset array
     bnc->fresh_message_tree.destroy();
-    bnc->fresh_message_tree.create_steal_sorted_array(&fresh_offsets, nfresh, n_in_this_buffer);
+    bnc->fresh_message_tree.create_steal_sorted_array(&fresh_offsets, nfresh, nfresh);
     bnc->stale_message_tree.destroy();
-    bnc->stale_message_tree.create_steal_sorted_array(&stale_offsets, nstale, n_in_this_buffer);
+    bnc->stale_message_tree.create_steal_sorted_array(&stale_offsets, nstale, nstale);
     bnc->broadcast_list.destroy();
-    bnc->broadcast_list.create_steal_sorted_array(&broadcast_offsets, nbroadcast_offsets, n_in_this_buffer);
+    bnc->broadcast_list.create_steal_sorted_array(&broadcast_offsets, nbroadcast, nbroadcast);
 }
 
 // dump a buffer to stderr
@@ -1776,7 +1695,7 @@ deserialize_and_upgrade_internal_node(FTNODE node,
         int32_t *fresh_offsets = nullptr;
         int32_t *broadcast_offsets = nullptr;
         int nfresh = 0;
-        int nbroadcast_offsets = 0;
+        int nbroadcast = 0;
 
         // We skip 'stale' offsets for upgraded nodes.
         if (sort_buffers) {
@@ -1811,8 +1730,8 @@ deserialize_and_upgrade_internal_node(FTNODE node,
                     dest = &fresh_offsets[nfresh];
                     nfresh++;
                 } else if (ft_msg_type_applies_all(type) || ft_msg_type_does_nothing(type)) {
-                    dest = &broadcast_offsets[nbroadcast_offsets];
-                    nbroadcast_offsets++;
+                    dest = &broadcast_offsets[nbroadcast];
+                    nbroadcast++;
                 } else {
                     abort();
                 }
@@ -1838,7 +1757,7 @@ deserialize_and_upgrade_internal_node(FTNODE node,
             bnc->fresh_message_tree.destroy();
             bnc->fresh_message_tree.create_steal_sorted_array(&fresh_offsets, nfresh, n_in_this_buffer);
             bnc->broadcast_list.destroy();
-            bnc->broadcast_list.create_steal_sorted_array(&broadcast_offsets, nbroadcast_offsets, n_in_this_buffer);
+            bnc->broadcast_list.create_steal_sorted_array(&broadcast_offsets, nbroadcast, n_in_this_buffer);
         }
     }
 

ft/msg_buffer.cc

@@ -110,7 +110,63 @@ void message_buffer::destroy() {
     }
 }
 
-void message_buffer::resize(size_t new_size) {
+void message_buffer::deserialize_from_rbuf(struct rbuf *rb,
+                                           int32_t **fresh_offsets, int32_t *nfresh,
+                                           int32_t **stale_offsets, int32_t *nstale,
+                                           int32_t **broadcast_offsets, int32_t *nbroadcast) {
+    // read the number of messages in this buffer
+    int n_in_this_buffer = rbuf_int(rb);
+    if (fresh_offsets != nullptr) {
+        XMALLOC_N(n_in_this_buffer, *fresh_offsets);
+    }
+    if (stale_offsets != nullptr) {
+        XMALLOC_N(n_in_this_buffer, *stale_offsets);
+    }
+    if (broadcast_offsets != nullptr) {
+        XMALLOC_N(n_in_this_buffer, *broadcast_offsets);
+    }
+
+    _resize(rb->size + 64); // rb->size is a good hint for how big the buffer will be
+
+    // read in each message individually
+    for (int i = 0; i < n_in_this_buffer; i++) {
+        bytevec key; ITEMLEN keylen;
+        bytevec val; ITEMLEN vallen;
+        // this is weird but it's necessary to pass icc and gcc together
+        unsigned char ctype = rbuf_char(rb);
+        enum ft_msg_type type = (enum ft_msg_type) ctype;
+        bool is_fresh = rbuf_char(rb);
+        MSN msn = rbuf_msn(rb);
+        XIDS xids;
+        xids_create_from_buffer(rb, &xids);
+        rbuf_bytes(rb, &key, &keylen); /* Returns a pointer into the rbuf. */
+        rbuf_bytes(rb, &val, &vallen);
+        int32_t *dest = nullptr;
+        if (ft_msg_type_applies_once(type)) {
+            if (is_fresh) {
+                dest = fresh_offsets ? *fresh_offsets + (*nfresh)++ : nullptr;
+            } else {
+                dest = stale_offsets ? *stale_offsets + (*nstale)++ : nullptr;
+            }
+        } else {
+            invariant(ft_msg_type_applies_all(type) || ft_msg_type_does_nothing(type));
+            dest = broadcast_offsets ? *broadcast_offsets + (*nbroadcast)++ : nullptr;
+        }
+
+        // TODO: Function to parse stuff out of an rbuf into an FT_MSG
+        DBT k, v;
+        FT_MSG_S msg = {
+            type, msn, xids,
+            .u = { .id = { toku_fill_dbt(&k, key, keylen), toku_fill_dbt(&v, val, vallen) } }
+        };
+        enqueue(&msg, is_fresh, dest);
+        xids_destroy(&xids);
+    }
+
+    invariant(num_entries() == n_in_this_buffer);
+}
+
+void message_buffer::_resize(size_t new_size) {
     XREALLOC_N(new_size, _memory);
     _memory_size = new_size;
 }
@@ -134,7 +190,7 @@ void message_buffer::enqueue(FT_MSG msg, bool is_fresh, int32_t *offset) {
     if (_memory == nullptr || need_space_total > _memory_size) {
         // resize the buffer to the next power of 2 greater than the needed space
         int next_2 = next_power_of_two(need_space_total);
-        resize(next_2);
+        _resize(next_2);
     }
     ITEMLEN keylen = ft_msg_get_keylen(msg);
     ITEMLEN datalen = ft_msg_get_vallen(msg);
@@ -212,6 +268,26 @@ bool message_buffer::equals(message_buffer *other) const {
             memcmp(_memory, other->_memory, _memory_used) == 0);
 }
 
+void message_buffer::serialize_to_wbuf(struct wbuf *wb) const {
+    wbuf_nocrc_int(wb, num_entries());
+    struct msg_serialize_fn {
+        struct wbuf *wb;
+        msg_serialize_fn(struct wbuf *w) : wb(w) { }
+        int operator()(FT_MSG msg, bool is_fresh) {
+            enum ft_msg_type type = (enum ft_msg_type) msg->type;
+            paranoid_invariant((int) type >= 0 && (int) type < 256);
+            wbuf_nocrc_char(wb, (unsigned char) type);
+            wbuf_nocrc_char(wb, (unsigned char) is_fresh);
+            wbuf_MSN(wb, msg->msn);
+            wbuf_nocrc_xids(wb, ft_msg_get_xids(msg));
+            wbuf_nocrc_bytes(wb, ft_msg_get_key(msg), ft_msg_get_keylen(msg));
+            wbuf_nocrc_bytes(wb, ft_msg_get_val(msg), ft_msg_get_vallen(msg));
+            return 0;
+        }
+    } serialize_fn(wb);
+    iterate(serialize_fn);
+}
+
 size_t message_buffer::msg_memsize_in_buffer(FT_MSG msg) {
     const uint32_t keylen = ft_msg_get_keylen(msg);
     const uint32_t datalen = ft_msg_get_vallen(msg);

ft/msg_buffer.h

@@ -102,7 +102,14 @@ class message_buffer {
 
     void destroy();
 
-    void resize(size_t new_size);
+    // effect: deserializes a message buffer from the given rbuf
+    // returns: *fresh_offsets (etc) malloc'd to be num_entries large and
+    //          populated with *nfresh (etc) offsets in the message buffer
+    // requires: if fresh_offsets (etc) != nullptr, then nfresh != nullptr
+    void deserialize_from_rbuf(struct rbuf *rb,
+                               int32_t **fresh_offsets, int32_t *nfresh,
+                               int32_t **stale_offsets, int32_t *nstale,
+                               int32_t **broadcast_offsets, int32_t *nbroadcast);
 
     void enqueue(FT_MSG msg, bool is_fresh, int32_t *offset);
 
@@ -139,9 +146,13 @@ class message_buffer {
 
     bool equals(message_buffer *other) const;
 
+    void serialize_to_wbuf(struct wbuf *wb) const;
+
     static size_t msg_memsize_in_buffer(FT_MSG msg);
 
 private:
+    void _resize(size_t new_size);
+
     // If this isn't packged, the compiler aligns the xids array and we waste a lot of space
     struct __attribute__((__packed__)) buffer_entry {
         unsigned int  keylen;