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+// Copyright 2011 The Kyua Authors.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright
+// notice, this list of conditions and the following disclaimer in the
+// documentation and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors
+// may be used to endorse or promote products derived from this software
+// without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "utils/stream.hpp"
+
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <stdexcept>
+
+#include "utils/format/macros.hpp"
+#include "utils/fs/path.hpp"
+#include "utils/sanity.hpp"
+
+namespace fs = utils::fs;
+
+
+namespace {
+
+
+/// Constant that represents the path to stdout.
+static const fs::path stdout_path("/dev/stdout");
+
+
+/// Constant that represents the path to stderr.
+static const fs::path stderr_path("/dev/stderr");
+
+
+} // anonymous namespace
+
+
+/// Opens a new file for output, respecting the stdout and stderr streams.
+///
+/// \param path The path to the output file to be created.
+///
+/// \return A pointer to a new output stream.
+std::auto_ptr< std::ostream >
+utils::open_ostream(const fs::path& path)
+{
+ std::auto_ptr< std::ostream > out;
+ if (path == stdout_path) {
+ out.reset(new std::ofstream());
+ out->copyfmt(std::cout);
+ out->clear(std::cout.rdstate());
+ out->rdbuf(std::cout.rdbuf());
+ } else if (path == stderr_path) {
+ out.reset(new std::ofstream());
+ out->copyfmt(std::cerr);
+ out->clear(std::cerr.rdstate());
+ out->rdbuf(std::cerr.rdbuf());
+ } else {
+ out.reset(new std::ofstream(path.c_str()));
+ if (!(*out)) {
+ throw std::runtime_error(F("Cannot open output file %s") % path);
+ }
+ }
+ INV(out.get() != NULL);
+ return out;
+}
+
+
+/// Gets the length of a stream.
+///
+/// \param is The input stream for which to calculate its length.
+///
+/// \return The length of the stream. This is of size_t type instead of
+/// directly std::streampos to simplify the caller. Some systems do not
+/// support comparing a std::streampos directly to an integer (see
+/// NetBSD 1.5.x), which is what we often want to do.
+///
+/// \throw std::exception If calculating the length fails due to a stream error.
+std::size_t
+utils::stream_length(std::istream& is)
+{
+ const std::streampos current_pos = is.tellg();
+ try {
+ is.seekg(0, std::ios::end);
+ const std::streampos length = is.tellg();
+ is.seekg(current_pos, std::ios::beg);
+ return static_cast< std::size_t >(length);
+ } catch (...) {
+ is.seekg(current_pos, std::ios::beg);
+ throw;
+ }
+}
+
+
+/// Reads a whole file into memory.
+///
+/// \param path The file to read.
+///
+/// \return A plain string containing the raw contents of the file.
+///
+/// \throw std::runtime_error If the file cannot be opened.
+std::string
+utils::read_file(const fs::path& path)
+{
+ std::ifstream input(path.c_str());
+ if (!input)
+ throw std::runtime_error(F("Failed to open '%s' for read") % path);
+ return read_stream(input);
+}
+
+
+/// Reads the whole contents of a stream into memory.
+///
+/// \param input The input stream from which to read.
+///
+/// \return A plain string containing the raw contents of the file.
+std::string
+utils::read_stream(std::istream& input)
+{
+ std::ostringstream buffer;
+
+ char tmp[1024];
+ while (input.good()) {
+ input.read(tmp, sizeof(tmp));
+ if (input.good() || input.eof()) {
+ buffer.write(tmp, input.gcount());
+ }
+ }
+
+ return buffer.str();
+}