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/*
* Copyright (C) 2012 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.
*/
#ifndef ART_LIBARTBASE_BASE_INDENTER_H_
#define ART_LIBARTBASE_BASE_INDENTER_H_
#include <ostream>
#include <streambuf>
#include <android-base/logging.h>
#include "macros.h"
namespace art {
constexpr char kIndentChar =' ';
constexpr size_t kIndentBy1Count = 2;
class Indenter : public std::streambuf {
public:
Indenter(std::streambuf* out, char text, size_t count)
: indent_next_(true), out_sbuf_(out),
text_{text, text, text, text, text, text, text, text},
count_(count) {}
private:
std::streamsize xsputn(const char* s, std::streamsize n) override {
std::streamsize result = n; // Aborts on failure.
const char* eol = static_cast<const char*>(memchr(s, '\n', n));
while (eol != nullptr) {
size_t to_write = eol + 1 - s;
Write(s, to_write);
s += to_write;
n -= to_write;
indent_next_ = true;
eol = static_cast<const char*>(memchr(s, '\n', n));
}
if (n != 0u) {
Write(s, n);
}
return result;
}
int_type overflow(int_type c) override {
if (UNLIKELY(c == std::char_traits<char>::eof())) {
out_sbuf_->pubsync();
return c;
}
char data[1] = { static_cast<char>(c) };
Write(data, 1u);
indent_next_ = (c == '\n');
return c;
}
int sync() override {
return out_sbuf_->pubsync();
}
void Write(const char* s, std::streamsize n) {
if (indent_next_) {
size_t remaining = count_;
while (remaining != 0u) {
size_t to_write = std::min(remaining, sizeof(text_));
RawWrite(text_, to_write);
remaining -= to_write;
}
indent_next_ = false;
}
RawWrite(s, n);
}
void RawWrite(const char* s, std::streamsize n) {
size_t written = out_sbuf_->sputn(s, n);
s += written;
n -= written;
while (n != 0u) {
out_sbuf_->pubsync();
written = out_sbuf_->sputn(s, n);
CHECK_NE(written, 0u) << "Error writing to buffer. Disk full?";
s += written;
n -= written;
}
}
bool indent_next_;
// Buffer to write output to.
std::streambuf* const out_sbuf_;
// Text output as indent.
const char text_[8];
// Number of times text is output.
size_t count_;
friend class VariableIndentationOutputStream;
DISALLOW_COPY_AND_ASSIGN(Indenter);
};
class VariableIndentationOutputStream {
public:
explicit VariableIndentationOutputStream(std::ostream* os, char text = kIndentChar)
: indenter_(os->rdbuf(), text, 0u),
indented_os_(&indenter_) {
}
std::ostream& Stream() {
return indented_os_;
}
size_t GetIndentation() const {
return indenter_.count_;
}
void IncreaseIndentation(size_t adjustment) {
indenter_.count_ += adjustment;
}
void DecreaseIndentation(size_t adjustment) {
DCHECK_GE(indenter_.count_, adjustment);
indenter_.count_ -= adjustment;
}
private:
Indenter indenter_;
std::ostream indented_os_;
DISALLOW_COPY_AND_ASSIGN(VariableIndentationOutputStream);
};
class ScopedIndentation {
public:
explicit ScopedIndentation(VariableIndentationOutputStream* vios,
size_t adjustment = kIndentBy1Count)
: vios_(vios),
adjustment_(adjustment) {
vios_->IncreaseIndentation(adjustment_);
}
~ScopedIndentation() {
vios_->DecreaseIndentation(adjustment_);
}
private:
VariableIndentationOutputStream* const vios_;
const size_t adjustment_;
DISALLOW_COPY_AND_ASSIGN(ScopedIndentation);
};
} // namespace art
#endif // ART_LIBARTBASE_BASE_INDENTER_H_
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