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// Copyright (C) 2012 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#include <dns/master_lexer_inputsource.h>
#include <dns/master_lexer.h>
#include <cerrno>
#include <cstring>
namespace isc {
namespace dns {
namespace master_lexer_internal {
namespace { // unnamed namespace
std::string
createStreamName(const std::istream& input_stream) {
std::stringstream ss;
ss << "stream-" << &input_stream;
return (ss.str());
}
} // end of unnamed namespace
// Explicit definition of class static constant. The value is given in the
// declaration so it's not needed here.
const int InputSource::END_OF_STREAM;
InputSource::InputSource(std::istream& input_stream) :
at_eof_(false),
line_(1),
saved_line_(line_),
buffer_pos_(0),
name_(createStreamName(input_stream)),
input_(input_stream)
{}
InputSource::InputSource(const char* filename) :
at_eof_(false),
line_(1),
saved_line_(line_),
buffer_pos_(0),
name_(filename),
input_(file_stream_)
{
errno = 0;
file_stream_.open(filename);
if (file_stream_.fail()) {
std::string error_txt("Error opening the input source file: ");
error_txt += filename;
if (errno != 0) {
error_txt += "; possible cause: ";
error_txt += std::strerror(errno);
}
isc_throw(OpenError, error_txt);
}
}
InputSource::~InputSource()
{
if (file_stream_.is_open()) {
file_stream_.close();
}
}
int
InputSource::getChar() {
if (buffer_pos_ == buffer_.size()) {
// We may have reached EOF at the last call to
// getChar(). at_eof_ will be set then. We then simply return
// early.
if (at_eof_) {
return (END_OF_STREAM);
}
// We are not yet at EOF. Read from the stream.
const int c = input_.get();
// Have we reached EOF now? If so, set at_eof_ and return early,
// but don't modify buffer_pos_ (which should still be equal to
// the size of buffer_).
if (input_.eof()) {
at_eof_ = true;
return (END_OF_STREAM);
}
// This has to come after the .eof() check as some
// implementations seem to check the eofbit also in .fail().
if (input_.fail()) {
isc_throw(MasterLexer::ReadError,
"Error reading from the input stream: " << getName());
}
buffer_.push_back(c);
}
const int c = buffer_[buffer_pos_];
++buffer_pos_;
if (c == '\n') {
++line_;
}
return (c);
}
void
InputSource::ungetChar() {
if (at_eof_) {
at_eof_ = false;
} else if (buffer_pos_ == 0) {
isc_throw(UngetBeforeBeginning,
"Cannot skip before the start of buffer");
} else {
--buffer_pos_;
if (buffer_[buffer_pos_] == '\n') {
--line_;
}
}
}
void
InputSource::ungetAll() {
buffer_pos_ = 0;
line_ = saved_line_;
at_eof_ = false;
}
void
InputSource::saveLine() {
saved_line_ = line_;
}
void
InputSource::compact() {
if (buffer_pos_ == buffer_.size()) {
buffer_.clear();
} else {
buffer_.erase(buffer_.begin(), buffer_.begin() + buffer_pos_);
}
buffer_pos_ = 0;
}
void
InputSource::mark() {
saveLine();
compact();
}
} // namespace master_lexer_internal
} // namespace dns
} // namespace isc
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