[Assorted-commits] SF.net SVN: assorted:[1236] ydb/trunk

[<yan...@us...>]

Revision: 1236
          http://assorted.svn.sourceforge.net/assorted/?rev=1236&view=rev
Author:   yangzhang
Date:     2009-02-26 03:17:16 +0000 (Thu, 26 Feb 2009)

Log Message:
-----------
- use ser_array adapter for arrays to stand in as the serialization type
  (instead of strings)
- fixed the types on the rb pb-expander methods
- added ser for ser_arrays
- removed pb_size; unreliable
- added some more notes

Modified Paths:
--------------
    ydb/trunk/README
    ydb/trunk/src/main.lzz.clamp
    ydb/trunk/src/ser.h

Modified: ydb/trunk/README
===================================================================
--- ydb/trunk/README	2009-02-26 03:15:58 UTC (rev 1235)
+++ ydb/trunk/README	2009-02-26 03:17:16 UTC (rev 1236)
@@ -446,7 +446,11 @@
   - almost no diff
   - 1: 362K
   - 2: 350K
-- TODO use arrays instead of strings for pb and avoid dyn alloc
+- DONE use arrays instead of strings for pb and avoid dyn alloc
+  - almost no diff
+  - 1: 362K
+  - 2: 355K
+- TODO make same changes for sending responses
 - TODO fix pb recovery
 
 - TODO refactor st_reader, etc. to be generic opportunistic buffered readers

Modified: ydb/trunk/src/main.lzz.clamp
===================================================================
--- ydb/trunk/src/main.lzz.clamp	2009-02-26 03:15:58 UTC (rev 1235)
+++ ydb/trunk/src/main.lzz.clamp	2009-02-26 03:17:16 UTC (rev 1236)
@@ -52,7 +52,6 @@
 #define map_t dense_hash_map
 typedef pair<int, int> pii;
 typedef map_t<int, int> mii;
-typedef string ser_t;
 
 template<typename T> void init_map(T &map) {}
 template<> void init_map(dense_hash_map<int, int> &map) {
@@ -256,6 +255,28 @@
 st_channel<pair<st_netfd_t, shared_ptr<string> > > msgs;
 
 /**
+ * Adapter for arrays to look like strings (for PB serialization).
+ */
+class ser_array
+{
+  commons::array<char> a_;
+  size_t size_;
+public:
+  ser_array(size_t size = buf_size) : a_(size), size_(0) {}
+  char *data() const { return a_.get(); }
+  size_t size() const { return size_; }
+  void clear() { size_ = 0; }
+  void stretch(size_t size) {
+    if (size > a_.size())
+      a_.reset(new char[size], size);
+    size_ = size;
+  }
+};
+
+//typedef string ser_t;
+typedef ser_array ser_t;
+
+/**
  * Serialization.
  *
  * TODO: experiment with which method is the fastest: using a string as shown
@@ -281,15 +302,18 @@
   copy(plen, plen + sizeof len, s.begin());
 }
 
-/**
- * Helper for getting the cached ByteSize of a message.
- */
-template <typename T>
-size_t
-pb_size(const T &msg) {
-  // GetCachedSize returns 0 if no cached size.
-  size_t len = msg.GetCachedSize();
-  return len == 0 ? msg.ByteSize() : len;
+template<typename T>
+void
+ser(ser_array &s, const T &msg)
+{
+  int len = msg.ByteSize();
+
+  // Grow the array as needed.
+  s.stretch(len + sizeof(uint32_t));
+
+  // Serialize message to a buffer with four-byte length prefix.
+  check(msg.SerializeToArray(s.data() + sizeof(uint32_t), len));
+  *reinterpret_cast<uint32_t*>(s.data()) = htonl(uint32_t(len));
 }
 
 /**
@@ -299,7 +323,7 @@
 void
 ser(ostream &s, const T &msg)
 {
-  uint32_t len = htonl(uint32_t(pb_size(msg)));
+  uint32_t len = htonl(uint32_t(msg.ByteSize()));
   s.write(reinterpret_cast<const char*>(&len), sizeof len);
   check(msg.SerializeToOstream(&s));
 }

Modified: ydb/trunk/src/ser.h
===================================================================
--- ydb/trunk/src/ser.h	2009-02-26 03:15:58 UTC (rev 1235)
+++ ydb/trunk/src/ser.h	2009-02-26 03:17:16 UTC (rev 1236)
@@ -34,11 +34,12 @@
 
 #define EXPAND_PB \
     bool AppendToString(string*) const { throw_operation_not_supported(); } \
+    bool SerializeToArray(void*, int) const { throw_operation_not_supported(); } \
     bool SerializeToString(string*) const { throw_operation_not_supported(); } \
     bool SerializeToOstream(ostream*) const { throw_operation_not_supported(); } \
-    bool ParseFromArray(void*, size_t) { throw_operation_not_supported(); } \
-    size_t GetCachedSize() const { throw_operation_not_supported(); } \
-    size_t ByteSize() const { throw_operation_not_supported(); } \
+    bool ParseFromArray(void*, int) { throw_operation_not_supported(); } \
+    int GetCachedSize() const { throw_operation_not_supported(); } \
+    int ByteSize() const { throw_operation_not_supported(); } \
 
 #define MAKE_TYPE_BATCH(name, ns, b) \
   struct name##_types { \


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