upload android base code part6

android/system/core/libmemunreachable/LineBuffer.cpp

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Copied from system/extras/memory_replay/LineBuffer.cpp
+// TODO(ccross): find a way to share between libmemunreachable and memory_replay?
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "LineBuffer.h"
+
+namespace android {
+
+LineBuffer::LineBuffer(int fd, char* buffer, size_t buffer_len)
+    : fd_(fd), buffer_(buffer), buffer_len_(buffer_len) {}
+
+bool LineBuffer::GetLine(char** line, size_t* line_len) {
+  while (true) {
+    if (bytes_ > 0) {
+      char* newline = reinterpret_cast<char*>(memchr(buffer_ + start_, '\n', bytes_));
+      if (newline != nullptr) {
+        *newline = '\0';
+        *line = buffer_ + start_;
+        start_ = newline - buffer_ + 1;
+        bytes_ -= newline - *line + 1;
+        *line_len = newline - *line;
+        return true;
+      }
+    }
+    if (start_ > 0) {
+      // Didn't find anything, copy the current to the front of the buffer.
+      memmove(buffer_, buffer_ + start_, bytes_);
+      start_ = 0;
+    }
+    ssize_t bytes = TEMP_FAILURE_RETRY(read(fd_, buffer_ + bytes_, buffer_len_ - bytes_ - 1));
+    if (bytes <= 0) {
+      if (bytes_ > 0) {
+        // The read data might not contain a nul terminator, so add one.
+        buffer_[bytes_] = '\0';
+        *line = buffer_ + start_;
+        *line_len = bytes_;
+        bytes_ = 0;
+        start_ = 0;
+        return true;
+      }
+      return false;
+    }
+    bytes_ += bytes;
+  }
+}
+
+}  // namespace android