Fix issue where stale result set might end up being read (this has never been reporte...

[m6w6/libmemcached] / libmemcached / get.cc

diff --git a/libmemcached/get.cc b/libmemcached/get.cc
index 1deb39765ea7d2a0162acfb9a6d67e789ab1f3b0..be7d9e5f66b226912f86ced59e7d9bf9e277e953 100644 (file)
--- a/libmemcached/get.cc
+++ b/libmemcached/get.cc
@@ -2,7 +2,7 @@
  * 
  *  Libmemcached library
  *
- *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
+ *  Copyright (C) 2011-2012 Data Differential, http://datadifferential.com/
  *  Copyright (C) 2006-2009 Brian Aker All rights reserved.
  *
  *  Redistribution and use in source and binary forms, with or without
@@ -117,10 +117,11 @@ char *memcached_get_by_key(memcached_st *ptr,
 
   if (value == NULL)
   {
-    if (ptr->get_key_failure && *error == MEMCACHED_NOTFOUND)
+    if (ptr->get_key_failure and *error == MEMCACHED_NOTFOUND)
     {
-      memcached_result_reset(&ptr->result);
-      memcached_return_t rc= ptr->get_key_failure(ptr, key, key_length, &ptr->result);
+      memcached_result_st key_failure_result;
+      memcached_result_st* result_ptr= memcached_result_create(ptr, &key_failure_result);
+      memcached_return_t rc= ptr->get_key_failure(ptr, key, key_length, result_ptr);
 
       /* On all failure drop to returning NULL */
       if (rc == MEMCACHED_SUCCESS or rc == MEMCACHED_BUFFERED)
@@ -135,12 +136,12 @@ char *memcached_get_by_key(memcached_st *ptr,
           }
 
           rc= memcached_set(ptr, key, key_length,
-                            (memcached_result_value(&ptr->result)),
-                            (memcached_result_length(&ptr->result)),
+                            (memcached_result_value(result_ptr)),
+                            (memcached_result_length(result_ptr)),
                             0,
-                            (memcached_result_flags(&ptr->result)));
+                            (memcached_result_flags(result_ptr)));
 
-          if (rc == MEMCACHED_BUFFERED && latch == 0)
+          if (rc == MEMCACHED_BUFFERED and latch == 0)
           {
             memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 0);
           }
@@ -148,20 +149,25 @@ char *memcached_get_by_key(memcached_st *ptr,
         else
         {
           rc= memcached_set(ptr, key, key_length,
-                            (memcached_result_value(&ptr->result)),
-                            (memcached_result_length(&ptr->result)),
+                            (memcached_result_value(result_ptr)),
+                            (memcached_result_length(result_ptr)),
                             0,
-                            (memcached_result_flags(&ptr->result)));
+                            (memcached_result_flags(result_ptr)));
         }
 
-        if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_BUFFERED)
+        if (rc == MEMCACHED_SUCCESS or rc == MEMCACHED_BUFFERED)
         {
           *error= rc;
-          *value_length= memcached_result_length(&ptr->result);
-          *flags= memcached_result_flags(&ptr->result);
-          return memcached_string_take_value(&ptr->result.value);
+          *value_length= memcached_result_length(result_ptr);
+          *flags= memcached_result_flags(result_ptr);
+          char *result_value=  memcached_string_take_value(&result_ptr->value);
+          memcached_result_free(result_ptr);
+
+          return result_value;
         }
       }
+
+      memcached_result_free(result_ptr);
     }
     assert_msg(ptr->query_id == query_id +1, "Programmer error, the query_id was not incremented.");
 
@@ -310,7 +316,7 @@ static memcached_return_t memcached_mget_by_key_real(memcached_st *ptr,
       }
       hosts_connected++;
 
-      if ((memcached_io_writev(instance, vector, 4, false)) == -1)
+      if ((memcached_io_writev(instance, vector, 4, false)) == false)
       {
         failures_occured_in_sending= true;
         continue;
@@ -321,7 +327,7 @@ static memcached_return_t memcached_mget_by_key_real(memcached_st *ptr,
     }
     else
     {
-      if ((memcached_io_writev(instance, (vector + 1), 3, false)) == -1)
+      if ((memcached_io_writev(instance, (vector + 1), 3, false)) == false)
       {
         memcached_server_response_reset(instance);
         failures_occured_in_sending= true;
@@ -368,13 +374,15 @@ static memcached_return_t memcached_mget_by_key_real(memcached_st *ptr,
 
   LIBMEMCACHED_MEMCACHED_MGET_END();
 
-  if (failures_occured_in_sending && success_happened)
+  if (failures_occured_in_sending and success_happened)
   {
     return MEMCACHED_SOME_ERRORS;
   }
 
   if (success_happened)
+  {
     return MEMCACHED_SUCCESS;
+  }
 
   return MEMCACHED_FAILURE; // Complete failure occurred
 }
@@ -518,7 +526,7 @@ static memcached_return_t simple_binary_mget(memcached_st *ptr,
       { keys[x], key_length[x] }
     };
 
-    if (memcached_io_writev(instance, vector, 3, flush) == -1)
+    if (memcached_io_writev(instance, vector, 3, flush) == false)
     {
       memcached_server_response_reset(instance);
       rc= MEMCACHED_SOME_ERRORS;
@@ -528,7 +536,7 @@ static memcached_return_t simple_binary_mget(memcached_st *ptr,
     /* We just want one pending response per server */
     memcached_server_response_reset(instance);
     memcached_server_response_increment(instance);
-    if ((x > 0 && x == ptr->io_key_prefetch) && memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
+    if ((x > 0 and x == ptr->io_key_prefetch) and memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
     {
       rc= MEMCACHED_SOME_ERRORS;
     }
@@ -584,7 +592,9 @@ static memcached_return_t replication_binary_mget(memcached_st *ptr,
   uint64_t randomize_read= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ);
 
   if (randomize_read)
+  {
     start= (uint32_t)random() % (uint32_t)(ptr->number_of_replicas + 1);
+  }
 
   /* Loop for each replica */
   for (uint32_t replica= 0; replica <= ptr->number_of_replicas; ++replica)
@@ -599,8 +609,10 @@ static memcached_return_t replication_binary_mget(memcached_st *ptr,
       uint32_t server= hash[x] + replica;
 
       /* In case of randomized reads */
-      if (randomize_read && ((server + start) <= (hash[x] + ptr->number_of_replicas)))
-        server += start;
+      if (randomize_read and ((server + start) <= (hash[x] + ptr->number_of_replicas)))
+      {
+        server+= start;
+      }
 
       while (server >= memcached_server_count(ptr))
       {
@@ -651,7 +663,7 @@ static memcached_return_t replication_binary_mget(memcached_st *ptr,
         { keys[x], key_length[x] }
       };
 
-      if (memcached_io_writev(instance, vector, 3, true) == -1)
+      if (memcached_io_writev(instance, vector, 3, true) == false)
       {
         memcached_io_reset(instance);
         dead_servers[server]= true;
@@ -689,7 +701,7 @@ static memcached_return_t binary_mget_by_key(memcached_st *ptr,
   uint32_t* hash= libmemcached_xvalloc(ptr, number_of_keys, uint32_t);
   bool* dead_servers= libmemcached_xcalloc(ptr, memcached_server_count(ptr), bool);
 
-  if (hash == NULL || dead_servers == NULL)
+  if (hash == NULL or dead_servers == NULL)
   {
     libmemcached_free(ptr, hash);
     libmemcached_free(ptr, dead_servers);