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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
// Original author: ekr@rtfm.com
#ifndef databuffer_h__
#define databuffer_h__
#include <algorithm>
#include <mozilla/UniquePtr.h>
#include <m_cpp_utils.h>
#include <nsISupportsImpl.h>
namespace mozilla {
class DataBuffer {
public:
DataBuffer() : data_(nullptr), len_(0), capacity_(0) {}
DataBuffer(const uint8_t *data, size_t len) {
Assign(data, len, len);
}
DataBuffer(const uint8_t *data, size_t len, size_t capacity) {
Assign(data, len, capacity);
}
// to ensure extra space for expansion
void Assign(const uint8_t *data, size_t len, size_t capacity) {
MOZ_RELEASE_ASSERT(len <= capacity);
Allocate(capacity); // sets len_ = capacity
memcpy(static_cast<void *>(data_.get()),
static_cast<const void *>(data), len);
len_ = len;
}
void Allocate(size_t capacity) {
data_.reset(new uint8_t[capacity ? capacity : 1]); // Don't depend on new [0].
len_ = capacity_ = capacity;
}
void EnsureCapacity(size_t capacity) {
if (capacity_ < capacity) {
uint8_t *new_data = new uint8_t[ capacity ? capacity : 1];
memcpy(static_cast<void *>(new_data),
static_cast<const void *>(data_.get()), len_);
data_.reset(new_data); // after copying! Deletes old data
capacity_ = capacity;
}
}
// used when something writes to the buffer (having checked
// capacity() or used EnsureCapacity()) and increased the length.
void SetLength(size_t len) {
MOZ_RELEASE_ASSERT(len <= capacity_);
len_ = len;
}
const uint8_t *data() const { return data_.get(); }
uint8_t *data() { return data_.get(); }
size_t len() const { return len_; }
size_t capacity() const { return capacity_; }
private:
UniquePtr<uint8_t[]> data_;
size_t len_;
size_t capacity_;
DISALLOW_COPY_ASSIGN(DataBuffer);
};
}
#endif
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