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// Copyright 2021 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 "media/formats/hls/source_string.h"
#include "base/strings/string_piece.h"
#include "base/strings/string_util.h"
#include "base/types/pass_key.h"
#include "media/formats/hls/parse_status.h"
namespace media::hls {
// static
template <>
SourceString SourceString::Create(base::PassKey<SourceLineIterator>,
size_t line,
base::StringPiece str) {
return SourceString(line, 1, str, {});
}
// static
template <>
ResolvedSourceString ResolvedSourceString::Create(
base::PassKey<VariableDictionary>,
size_t line,
size_t column,
base::StringPiece str,
ResolvedSourceStringState resolution_state) {
return ResolvedSourceString(line, column, str, resolution_state);
}
// static
template <typename ResolutionState>
GenericSourceString<ResolutionState>
GenericSourceString<ResolutionState>::CreateForTesting(base::StringPiece str) {
return GenericSourceString::CreateForTesting(1, 1, str);
}
// static
template <>
SourceString SourceString::CreateForTesting(size_t line,
size_t column,
base::StringPiece str) {
return SourceString::CreateForTesting(line, column, str, {});
}
// static
template <>
ResolvedSourceString ResolvedSourceString::CreateForTesting(
size_t line,
size_t column,
base::StringPiece str) {
return ResolvedSourceString::CreateForTesting(
line, column, str,
ResolvedSourceStringState{.contains_substitutions = false});
}
// static
template <typename ResolutionState>
GenericSourceString<ResolutionState>
GenericSourceString<ResolutionState>::CreateForTesting(
size_t line,
size_t column,
base::StringPiece str,
ResolutionState resolution_state) {
return GenericSourceString(line, column, str, resolution_state);
}
template <typename ResolutionState>
GenericSourceString<ResolutionState>
GenericSourceString<ResolutionState>::Substr(size_t pos, size_t count) const {
const auto column = column_ + pos;
return GenericSourceString(line_, column, str_.substr(pos, count),
resolution_state_);
}
template <typename ResolutionState>
GenericSourceString<ResolutionState>
GenericSourceString<ResolutionState>::Consume(size_t count) {
count = std::min(count, str_.size());
auto consumed = Substr(0, count);
*this = Substr(count);
return consumed;
}
template <typename ResolutionState>
GenericSourceString<ResolutionState>
GenericSourceString<ResolutionState>::ConsumeDelimiter(char c) {
const auto index = Str().find_first_of(c);
const auto prefix = Consume(index);
Consume(1);
return prefix;
}
template <>
ResolvedSourceString SourceString::SkipVariableSubstitution() const {
return ResolvedSourceString(
Line(), Column(), Str(),
ResolvedSourceStringState{.contains_substitutions = false});
}
template <typename ResolutionState>
void GenericSourceString<ResolutionState>::TrimStart() {
auto start = Str().find_first_not_of(" \t");
Consume(start);
}
template <>
bool SourceString::ContainsSubstitutions() const {
return false;
}
template <>
bool ResolvedSourceString::ContainsSubstitutions() const {
return resolution_state_.contains_substitutions;
}
template <typename ResolutionState>
GenericSourceString<ResolutionState>::GenericSourceString(
size_t line,
size_t column,
base::StringPiece str,
ResolutionState resolution_state)
: line_(line),
column_(column),
str_(str),
resolution_state_(resolution_state) {}
SourceLineIterator::SourceLineIterator(base::StringPiece source)
: current_line_(1), source_(source) {}
ParseStatus::Or<SourceString> SourceLineIterator::Next() {
if (source_.empty()) {
return ParseStatusCode::kReachedEOF;
}
const auto line_end = source_.find_first_of("\r\n");
if (line_end == base::StringPiece::npos) {
return ParseStatusCode::kInvalidEOL;
}
const auto line_content = source_.substr(0, line_end);
const auto following = source_.substr(line_end);
// Trim (and validate) newline sequence from the following text
if (base::StartsWith(following, "\n")) {
source_ = following.substr(1);
} else if (base::StartsWith(following, "\r\n")) {
source_ = following.substr(2);
} else {
return ParseStatusCode::kInvalidEOL;
}
const auto line_number = current_line_;
current_line_ += 1;
return SourceString::Create({}, line_number, line_content);
}
// These forward declarations tell the compiler that we will use
// `GenericSourceString` with these arguments, allowing us to keep these
// definitions in our .cc without causing linker errors. This also means if
// anyone tries to instantiate a `GenericSourceString` with anything but these
// two specializations they'll most likely get linker errors.
template class MEDIA_EXPORT GenericSourceString<SourceStringState>;
template class MEDIA_EXPORT GenericSourceString<ResolvedSourceStringState>;
} // namespace media::hls
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