| /* |
| * Copyright (C) 2011 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. |
| */ |
| #include "ReadBuffer.h" |
| #include <string.h> |
| #include <assert.h> |
| #include <limits.h> |
| #include "ErrorLog.h" |
| |
| ReadBuffer::ReadBuffer(IOStream *stream, size_t bufsize) |
| { |
| m_size = bufsize; |
| m_stream = stream; |
| m_buf = (unsigned char*)malloc(m_size*sizeof(unsigned char)); |
| m_validData = 0; |
| m_readPtr = m_buf; |
| } |
| |
| ReadBuffer::~ReadBuffer() |
| { |
| free(m_buf); |
| } |
| |
| int ReadBuffer::getData() |
| { |
| if ((m_validData > 0) && (m_readPtr > m_buf)) { |
| memmove(m_buf, m_readPtr, m_validData); |
| } |
| // get fresh data into the buffer; |
| size_t len = m_size - m_validData; |
| if (len==0) { |
| //we need to inc our buffer |
| size_t new_size = m_size*2; |
| unsigned char* new_buf; |
| if (new_size < m_size) { // overflow check |
| new_size = INT_MAX; |
| } |
| |
| new_buf = (unsigned char*)realloc(m_buf, new_size); |
| if (!new_buf) { |
| ERR("Failed to alloc %zu bytes for ReadBuffer\n", new_size); |
| return -1; |
| } |
| m_size = new_size; |
| m_buf = new_buf; |
| len = m_size - m_validData; |
| } |
| m_readPtr = m_buf; |
| if (NULL != m_stream->read(m_buf + m_validData, &len)) { |
| m_validData += len; |
| return len; |
| } |
| return -1; |
| } |
| |
| void ReadBuffer::consume(size_t amount) |
| { |
| assert(amount <= m_validData); |
| m_validData -= amount; |
| m_readPtr += amount; |
| } |