From f448422a04e56ed83fa52f2241243b49af69d6b8 Mon Sep 17 00:00:00 2001
From: chengtbf <472491134@qq.com>
Date: Sat, 7 Apr 2018 17:59:39 +0800
Subject: [PATCH] in stream read memcpy (#773)

Former-commit-id: 652052bbfd9fec4cd4dc8012a71d18cf8812a8e7
---
 .../persistent_in_stream_without_local_copy.cpp      | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/oneflow/core/persistence/persistent_in_stream_without_local_copy.cpp b/oneflow/core/persistence/persistent_in_stream_without_local_copy.cpp
index 962f9ac48a..5f4846cb82 100644
--- a/oneflow/core/persistence/persistent_in_stream_without_local_copy.cpp
+++ b/oneflow/core/persistence/persistent_in_stream_without_local_copy.cpp
@@ -1,5 +1,6 @@
 #include "oneflow/core/persistence/persistent_in_stream_without_local_copy.h"
 #include "oneflow/core/job/job_desc.h"
+#include <cstring>
 
 namespace oneflow {
 
@@ -23,10 +24,15 @@ int32_t PersistentInStreamWithoutLocalCopy::ReadLine(std::string* l) {
 
 int32_t PersistentInStreamWithoutLocalCopy::Read(char* s, size_t n) {
   if (IsEof()) { return -1; }
-  while (n--) {
+  while (n) {
     if (cur_buf_begin_ == cur_buf_end_) { UpdateBuffer(); }
-    CHECK_NE(cur_buf_begin_, cur_buf_end_);
-    *s++ = *cur_buf_begin_++;
+    CHECK_LT(cur_buf_begin_, cur_buf_end_);
+    int64_t copy_size =
+        std::min(cur_buf_end_ - cur_buf_begin_, static_cast<int64_t>(n));
+    std::memcpy(s, cur_buf_begin_, static_cast<size_t>(copy_size));
+    s += copy_size;
+    cur_buf_begin_ += copy_size;
+    n -= copy_size;
   }
   return 0;
 }
-- 
GitLab