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- // Copyright 2016 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 "pdf/loader/url_loader_wrapper_impl.h"
- #include <stddef.h>
- #include <stdint.h>
- #include <stdlib.h>
- #include <string.h>
- #include <memory>
- #include <string>
- #include <utility>
- #include "base/bind.h"
- #include "base/callback.h"
- #include "base/check_op.h"
- #include "base/containers/span.h"
- #include "base/location.h"
- #include "base/strings/string_util.h"
- #include "base/strings/stringprintf.h"
- #include "net/http/http_util.h"
- #include "pdf/loader/url_loader.h"
- #include "ui/gfx/range/range.h"
- namespace chrome_pdf {
- namespace {
- // We should read with delay to prevent block UI thread, and reduce CPU usage.
- constexpr base::TimeDelta kReadDelayMs = base::Milliseconds(2);
- UrlRequest MakeRangeRequest(const std::string& url,
- const std::string& referrer_url,
- uint32_t position,
- uint32_t size) {
- UrlRequest request;
- request.url = url;
- request.method = "GET";
- request.ignore_redirects = true;
- request.custom_referrer_url = referrer_url;
- // According to rfc2616, byte range specifies position of the first and last
- // bytes in the requested range inclusively. Therefore we should subtract 1
- // from the position + size, to get index of the last byte that needs to be
- // downloaded.
- request.headers =
- base::StringPrintf("Range: bytes=%d-%d", position, position + size - 1);
- return request;
- }
- bool GetByteRangeFromStr(const std::string& content_range_str,
- int* start,
- int* end) {
- std::string range = content_range_str;
- if (!base::StartsWith(range, "bytes", base::CompareCase::INSENSITIVE_ASCII))
- return false;
- range = range.substr(strlen("bytes"));
- std::string::size_type pos = range.find('-');
- std::string range_end;
- if (pos != std::string::npos)
- range_end = range.substr(pos + 1);
- base::TrimWhitespaceASCII(range, base::TRIM_LEADING, &range);
- base::TrimWhitespaceASCII(range_end, base::TRIM_LEADING, &range_end);
- *start = atoi(range.c_str());
- *end = atoi(range_end.c_str());
- return true;
- }
- // If the headers have a byte-range response, writes the start and end
- // positions and returns true if at least the start position was parsed.
- // The end position will be set to 0 if it was not found or parsed from the
- // response.
- // Returns false if not even a start position could be parsed.
- bool GetByteRangeFromHeaders(const std::string& headers, int* start, int* end) {
- net::HttpUtil::HeadersIterator it(headers.begin(), headers.end(), "\n");
- while (it.GetNext()) {
- if (base::EqualsCaseInsensitiveASCII(it.name_piece(), "content-range")) {
- if (GetByteRangeFromStr(it.values().c_str(), start, end))
- return true;
- }
- }
- return false;
- }
- bool IsDoubleEndLineAtEnd(const char* buffer, int size) {
- if (size < 2)
- return false;
- if (buffer[size - 1] == '\n' && buffer[size - 2] == '\n')
- return true;
- if (size < 4)
- return false;
- return buffer[size - 1] == '\n' && buffer[size - 2] == '\r' &&
- buffer[size - 3] == '\n' && buffer[size - 4] == '\r';
- }
- } // namespace
- URLLoaderWrapperImpl::URLLoaderWrapperImpl(
- std::unique_ptr<UrlLoader> url_loader)
- : url_loader_(std::move(url_loader)) {
- SetHeadersFromLoader();
- }
- URLLoaderWrapperImpl::~URLLoaderWrapperImpl() {
- Close();
- }
- int URLLoaderWrapperImpl::GetContentLength() const {
- return content_length_;
- }
- bool URLLoaderWrapperImpl::IsAcceptRangesBytes() const {
- return accept_ranges_bytes_;
- }
- bool URLLoaderWrapperImpl::IsContentEncoded() const {
- return content_encoded_;
- }
- std::string URLLoaderWrapperImpl::GetContentType() const {
- return content_type_;
- }
- std::string URLLoaderWrapperImpl::GetContentDisposition() const {
- return content_disposition_;
- }
- int URLLoaderWrapperImpl::GetStatusCode() const {
- return url_loader_->response().status_code;
- }
- bool URLLoaderWrapperImpl::IsMultipart() const {
- return is_multipart_;
- }
- bool URLLoaderWrapperImpl::GetByteRangeStart(int* start) const {
- DCHECK(start);
- *start = byte_range_.start();
- return byte_range_.IsValid();
- }
- void URLLoaderWrapperImpl::Close() {
- url_loader_->Close();
- read_starter_.Stop();
- }
- void URLLoaderWrapperImpl::OpenRange(const std::string& url,
- const std::string& referrer_url,
- uint32_t position,
- uint32_t size,
- base::OnceCallback<void(int)> callback) {
- url_loader_->Open(
- MakeRangeRequest(url, referrer_url, position, size),
- base::BindOnce(&URLLoaderWrapperImpl::DidOpen, weak_factory_.GetWeakPtr(),
- std::move(callback)));
- }
- void URLLoaderWrapperImpl::ReadResponseBody(
- char* buffer,
- int buffer_size,
- base::OnceCallback<void(int)> callback) {
- buffer_ = buffer;
- buffer_size_ = buffer_size;
- read_starter_.Start(
- FROM_HERE, kReadDelayMs,
- base::BindOnce(&URLLoaderWrapperImpl::ReadResponseBodyImpl,
- base::Unretained(this), std::move(callback)));
- }
- void URLLoaderWrapperImpl::ReadResponseBodyImpl(
- base::OnceCallback<void(int)> callback) {
- url_loader_->ReadResponseBody(
- base::make_span(buffer_.get(), buffer_size_),
- base::BindOnce(&URLLoaderWrapperImpl::DidRead, weak_factory_.GetWeakPtr(),
- std::move(callback)));
- }
- void URLLoaderWrapperImpl::ParseHeaders(const std::string& response_headers) {
- content_length_ = -1;
- accept_ranges_bytes_ = false;
- content_encoded_ = false;
- content_type_.clear();
- content_disposition_.clear();
- multipart_boundary_.clear();
- byte_range_ = gfx::Range::InvalidRange();
- is_multipart_ = false;
- if (response_headers.empty())
- return;
- net::HttpUtil::HeadersIterator it(response_headers.begin(),
- response_headers.end(), "\n");
- while (it.GetNext()) {
- base::StringPiece name = it.name_piece();
- if (base::EqualsCaseInsensitiveASCII(name, "content-length")) {
- content_length_ = atoi(it.values().c_str());
- } else if (base::EqualsCaseInsensitiveASCII(name, "accept-ranges")) {
- accept_ranges_bytes_ =
- base::EqualsCaseInsensitiveASCII(it.values(), "bytes");
- } else if (base::EqualsCaseInsensitiveASCII(name, "content-encoding")) {
- content_encoded_ = true;
- } else if (base::EqualsCaseInsensitiveASCII(name, "content-type")) {
- content_type_ = it.values();
- size_t semi_colon_pos = content_type_.find(';');
- if (semi_colon_pos != std::string::npos) {
- content_type_ = content_type_.substr(0, semi_colon_pos);
- }
- base::TrimWhitespaceASCII(content_type_, base::TRIM_ALL, &content_type_);
- // multipart boundary.
- std::string type = base::ToLowerASCII(it.values_piece());
- if (base::StartsWith(type, "multipart/", base::CompareCase::SENSITIVE)) {
- const char* boundary = strstr(type.c_str(), "boundary=");
- DCHECK(boundary);
- if (boundary) {
- multipart_boundary_ = std::string(boundary + 9);
- is_multipart_ = !multipart_boundary_.empty();
- }
- }
- } else if (base::EqualsCaseInsensitiveASCII(name, "content-disposition")) {
- content_disposition_ = it.values();
- } else if (base::EqualsCaseInsensitiveASCII(name, "content-range")) {
- int start = 0;
- int end = 0;
- if (GetByteRangeFromStr(it.values().c_str(), &start, &end)) {
- byte_range_ = gfx::Range(start, end);
- }
- }
- }
- }
- void URLLoaderWrapperImpl::DidOpen(base::OnceCallback<void(int)> callback,
- int32_t result) {
- SetHeadersFromLoader();
- std::move(callback).Run(result);
- }
- void URLLoaderWrapperImpl::DidRead(base::OnceCallback<void(int)> callback,
- int32_t result) {
- if (multi_part_processed_) {
- // Reset this flag so we look inside the buffer in calls of DidRead for this
- // response only once. Note that this code DOES NOT handle multi part
- // responses with more than one part (we don't issue them at the moment, so
- // they shouldn't arrive).
- is_multipart_ = false;
- }
- if (result <= 0 || !is_multipart_) {
- std::move(callback).Run(result);
- return;
- }
- if (result <= 2) {
- // TODO(art-snake): Accumulate data for parse headers.
- std::move(callback).Run(result);
- return;
- }
- char* start = buffer_;
- size_t length = result;
- multi_part_processed_ = true;
- for (int i = 2; i < result; ++i) {
- if (IsDoubleEndLineAtEnd(buffer_, i)) {
- int start_pos = 0;
- int end_pos = 0;
- if (GetByteRangeFromHeaders(std::string(buffer_.get(), i), &start_pos,
- &end_pos)) {
- byte_range_ = gfx::Range(start_pos, end_pos);
- start += i;
- length -= i;
- }
- break;
- }
- }
- result = length;
- if (result == 0) {
- // Continue receiving.
- return ReadResponseBodyImpl(std::move(callback));
- }
- DCHECK_GT(result, 0);
- memmove(buffer_, start, result);
- std::move(callback).Run(result);
- }
- void URLLoaderWrapperImpl::SetHeadersFromLoader() {
- ParseHeaders(url_loader_->response().headers);
- }
- } // namespace chrome_pdf
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