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- // Copyright 2014 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #include "base/big_endian.h"
- #include <string.h>
- #include "base/numerics/checked_math.h"
- #include "base/strings/string_piece.h"
- namespace base {
- BigEndianReader BigEndianReader::FromStringPiece(
- base::StringPiece string_piece) {
- return BigEndianReader(base::as_bytes(base::make_span(string_piece)));
- }
- BigEndianReader::BigEndianReader(const uint8_t* buf, size_t len)
- : ptr_(buf), end_(ptr_ + len) {
- // Ensure `len` does not cause `end_` to wrap around.
- CHECK_GE(end_, ptr_);
- }
- BigEndianReader::BigEndianReader(base::span<const uint8_t> buf)
- : ptr_(buf.data()), end_(buf.data() + buf.size()) {}
- bool BigEndianReader::Skip(size_t len) {
- if (len > remaining())
- return false;
- ptr_ += len;
- return true;
- }
- bool BigEndianReader::ReadBytes(void* out, size_t len) {
- if (len > remaining())
- return false;
- memcpy(out, ptr_, len);
- ptr_ += len;
- return true;
- }
- bool BigEndianReader::ReadPiece(base::StringPiece* out, size_t len) {
- if (len > remaining())
- return false;
- *out = base::StringPiece(reinterpret_cast<const char*>(ptr_), len);
- ptr_ += len;
- return true;
- }
- bool BigEndianReader::ReadSpan(base::span<const uint8_t>* out, size_t len) {
- if (len > remaining())
- return false;
- *out = base::make_span(ptr_, len);
- ptr_ += len;
- return true;
- }
- template<typename T>
- bool BigEndianReader::Read(T* value) {
- if (sizeof(T) > remaining())
- return false;
- ReadBigEndian<T>(ptr_, value);
- ptr_ += sizeof(T);
- return true;
- }
- bool BigEndianReader::ReadU8(uint8_t* value) {
- return Read(value);
- }
- bool BigEndianReader::ReadU16(uint16_t* value) {
- return Read(value);
- }
- bool BigEndianReader::ReadU32(uint32_t* value) {
- return Read(value);
- }
- bool BigEndianReader::ReadU64(uint64_t* value) {
- return Read(value);
- }
- template <typename T>
- bool BigEndianReader::ReadLengthPrefixed(base::StringPiece* out) {
- T t_len;
- if (!Read(&t_len))
- return false;
- size_t len = strict_cast<size_t>(t_len);
- const uint8_t* original_ptr = ptr_;
- if (!Skip(len)) {
- ptr_ -= sizeof(T);
- return false;
- }
- *out = base::StringPiece(reinterpret_cast<const char*>(original_ptr), len);
- return true;
- }
- bool BigEndianReader::ReadU8LengthPrefixed(base::StringPiece* out) {
- return ReadLengthPrefixed<uint8_t>(out);
- }
- bool BigEndianReader::ReadU16LengthPrefixed(base::StringPiece* out) {
- return ReadLengthPrefixed<uint16_t>(out);
- }
- BigEndianWriter::BigEndianWriter(char* buf, size_t len)
- : ptr_(buf), end_(ptr_ + len) {
- // Ensure `len` does not cause `end_` to wrap around.
- CHECK_GE(end_, ptr_);
- }
- bool BigEndianWriter::Skip(size_t len) {
- if (len > remaining())
- return false;
- ptr_ += len;
- return true;
- }
- bool BigEndianWriter::WriteBytes(const void* buf, size_t len) {
- if (len > remaining())
- return false;
- memcpy(ptr_, buf, len);
- ptr_ += len;
- return true;
- }
- template<typename T>
- bool BigEndianWriter::Write(T value) {
- if (sizeof(T) > remaining())
- return false;
- WriteBigEndian<T>(ptr_, value);
- ptr_ += sizeof(T);
- return true;
- }
- bool BigEndianWriter::WriteU8(uint8_t value) {
- return Write(value);
- }
- bool BigEndianWriter::WriteU16(uint16_t value) {
- return Write(value);
- }
- bool BigEndianWriter::WriteU32(uint32_t value) {
- return Write(value);
- }
- bool BigEndianWriter::WriteU64(uint64_t value) {
- return Write(value);
- }
- } // namespace base
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