diff options
Diffstat (limited to 'ext/iostream3')
| -rw-r--r-- | ext/iostream3/README | 35 | ||||
| -rw-r--r-- | ext/iostream3/SConscript | 46 | ||||
| -rw-r--r-- | ext/iostream3/TODO | 17 | ||||
| -rw-r--r-- | ext/iostream3/test.cc | 50 | ||||
| -rw-r--r-- | ext/iostream3/zfstream.cc | 479 | ||||
| -rw-r--r-- | ext/iostream3/zfstream.h | 466 |
6 files changed, 1093 insertions, 0 deletions
diff --git a/ext/iostream3/README b/ext/iostream3/README new file mode 100644 index 000000000..f7b319ab9 --- /dev/null +++ b/ext/iostream3/README @@ -0,0 +1,35 @@ +These classes provide a C++ stream interface to the zlib library. It allows you +to do things like: + + gzofstream outf("blah.gz"); + outf << "These go into the gzip file " << 123 << endl; + +It does this by deriving a specialized stream buffer for gzipped files, which is +the way Stroustrup would have done it. :-> + +The gzifstream and gzofstream classes were originally written by Kevin Ruland +and made available in the zlib contrib/iostream directory. The older version still +compiles under gcc 2.xx, but not under gcc 3.xx, which sparked the development of +this version. + +The new classes are as standard-compliant as possible, closely following the +approach of the standard library's fstream classes. It compiles under gcc versions +3.2 and 3.3, but not under gcc 2.xx. This is mainly due to changes in the standard +library naming scheme. The new version of gzifstream/gzofstream/gzfilebuf differs +from the previous one in the following respects: +- added showmanyc +- added setbuf, with support for unbuffered output via setbuf(0,0) +- a few bug fixes of stream behavior +- gzipped output file opened with default compression level instead of maximum level +- setcompressionlevel()/strategy() members replaced by single setcompression() + +The code is provided "as is", with the permission to use, copy, modify, distribute +and sell it for any purpose without fee. + +Ludwig Schwardt +<schwardt@sun.ac.za> + +DSP Lab +Electrical & Electronic Engineering Department +University of Stellenbosch +South Africa diff --git a/ext/iostream3/SConscript b/ext/iostream3/SConscript new file mode 100644 index 000000000..f8b5461a2 --- /dev/null +++ b/ext/iostream3/SConscript @@ -0,0 +1,46 @@ +# -*- mode:python -*- + +# Copyright (c) 2015 ARM Limited +# All rights reserved. +# +# The license below extends only to copyright in the software and shall +# not be construed as granting a license to any other intellectual +# property including but not limited to intellectual property relating +# to a hardware implementation of the functionality of the software +# licensed hereunder. You may use the software subject to the license +# terms below provided that you ensure that this notice is replicated +# unmodified and in its entirety in all distributions of the software, +# modified or unmodified, in source code or in binary form. +# +# 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 the copyright holders 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. +# +# Authors: Andreas Hansson + +Import('main') + +main.Library('iostream3', [main.SharedObject('zfstream.cc')]) + +main.Prepend(CPPPATH=Dir('.')) +main.Append(LIBS=['iostream3']) +main.Prepend(LIBPATH=[Dir('.')]) diff --git a/ext/iostream3/TODO b/ext/iostream3/TODO new file mode 100644 index 000000000..7032f97be --- /dev/null +++ b/ext/iostream3/TODO @@ -0,0 +1,17 @@ +Possible upgrades to gzfilebuf: + +- The ability to do putback (e.g. putbackfail) + +- The ability to seek (zlib supports this, but could be slow/tricky) + +- Simultaneous read/write access (does it make sense?) + +- Support for ios_base::ate open mode + +- Locale support? + +- Check public interface to see which calls give problems + (due to dependence on library internals) + +- Override operator<<(ostream&, gzfilebuf*) to allow direct copying + of stream buffer to stream ( i.e. os << is.rdbuf(); ) diff --git a/ext/iostream3/test.cc b/ext/iostream3/test.cc new file mode 100644 index 000000000..94235334f --- /dev/null +++ b/ext/iostream3/test.cc @@ -0,0 +1,50 @@ +/* + * Test program for gzifstream and gzofstream + * + * by Ludwig Schwardt <schwardt@sun.ac.za> + * original version by Kevin Ruland <kevin@rodin.wustl.edu> + */ + +#include "zfstream.h" +#include <iostream> // for cout + +int main() { + + gzofstream outf; + gzifstream inf; + char buf[80]; + + outf.open("test1.txt.gz"); + outf << "The quick brown fox sidestepped the lazy canine\n" + << 1.3 << "\nPlan " << 9 << std::endl; + outf.close(); + std::cout << "Wrote the following message to 'test1.txt.gz' (check with zcat or zless):\n" + << "The quick brown fox sidestepped the lazy canine\n" + << 1.3 << "\nPlan " << 9 << std::endl; + + std::cout << "\nReading 'test1.txt.gz' (buffered) produces:\n"; + inf.open("test1.txt.gz"); + while (inf.getline(buf,80,'\n')) { + std::cout << buf << "\t(" << inf.rdbuf()->in_avail() << " chars left in buffer)\n"; + } + inf.close(); + + outf.rdbuf()->pubsetbuf(0,0); + outf.open("test2.txt.gz"); + outf << setcompression(Z_NO_COMPRESSION) + << "The quick brown fox sidestepped the lazy canine\n" + << 1.3 << "\nPlan " << 9 << std::endl; + outf.close(); + std::cout << "\nWrote the same message to 'test2.txt.gz' in uncompressed form"; + + std::cout << "\nReading 'test2.txt.gz' (unbuffered) produces:\n"; + inf.rdbuf()->pubsetbuf(0,0); + inf.open("test2.txt.gz"); + while (inf.getline(buf,80,'\n')) { + std::cout << buf << "\t(" << inf.rdbuf()->in_avail() << " chars left in buffer)\n"; + } + inf.close(); + + return 0; + +} diff --git a/ext/iostream3/zfstream.cc b/ext/iostream3/zfstream.cc new file mode 100644 index 000000000..94eb93344 --- /dev/null +++ b/ext/iostream3/zfstream.cc @@ -0,0 +1,479 @@ +/* + * A C++ I/O streams interface to the zlib gz* functions + * + * by Ludwig Schwardt <schwardt@sun.ac.za> + * original version by Kevin Ruland <kevin@rodin.wustl.edu> + * + * This version is standard-compliant and compatible with gcc 3.x. + */ + +#include "zfstream.h" +#include <cstring> // for strcpy, strcat, strlen (mode strings) +#include <cstdio> // for BUFSIZ + +// Internal buffer sizes (default and "unbuffered" versions) +#define BIGBUFSIZE BUFSIZ +#define SMALLBUFSIZE 1 + +/*****************************************************************************/ + +// Default constructor +gzfilebuf::gzfilebuf() +: file(NULL), io_mode(std::ios_base::openmode(0)), own_fd(false), + buffer(NULL), buffer_size(BIGBUFSIZE), own_buffer(true) +{ + // No buffers to start with + this->disable_buffer(); +} + +// Destructor +gzfilebuf::~gzfilebuf() +{ + // Sync output buffer and close only if responsible for file + // (i.e. attached streams should be left open at this stage) + this->sync(); + if (own_fd) + this->close(); + // Make sure internal buffer is deallocated + this->disable_buffer(); +} + +// Set compression level and strategy +int +gzfilebuf::setcompression(int comp_level, + int comp_strategy) +{ + return gzsetparams(file, comp_level, comp_strategy); +} + +// Open gzipped file +gzfilebuf* +gzfilebuf::open(const char *name, + std::ios_base::openmode mode) +{ + // Fail if file already open + if (this->is_open()) + return NULL; + // Don't support simultaneous read/write access (yet) + if ((mode & std::ios_base::in) && (mode & std::ios_base::out)) + return NULL; + + // Build mode string for gzopen and check it [27.8.1.3.2] + char char_mode[6] = "\0\0\0\0\0"; + if (!this->open_mode(mode, char_mode)) + return NULL; + + // Attempt to open file + if ((file = gzopen(name, char_mode)) == NULL) + return NULL; + + // On success, allocate internal buffer and set flags + this->enable_buffer(); + io_mode = mode; + own_fd = true; + return this; +} + +// Attach to gzipped file +gzfilebuf* +gzfilebuf::attach(int fd, + std::ios_base::openmode mode) +{ + // Fail if file already open + if (this->is_open()) + return NULL; + // Don't support simultaneous read/write access (yet) + if ((mode & std::ios_base::in) && (mode & std::ios_base::out)) + return NULL; + + // Build mode string for gzdopen and check it [27.8.1.3.2] + char char_mode[6] = "\0\0\0\0\0"; + if (!this->open_mode(mode, char_mode)) + return NULL; + + // Attempt to attach to file + if ((file = gzdopen(fd, char_mode)) == NULL) + return NULL; + + // On success, allocate internal buffer and set flags + this->enable_buffer(); + io_mode = mode; + own_fd = false; + return this; +} + +// Close gzipped file +gzfilebuf* +gzfilebuf::close() +{ + // Fail immediately if no file is open + if (!this->is_open()) + return NULL; + // Assume success + gzfilebuf* retval = this; + // Attempt to sync and close gzipped file + if (this->sync() == -1) + retval = NULL; + if (gzclose(file) < 0) + retval = NULL; + // File is now gone anyway (postcondition [27.8.1.3.8]) + file = NULL; + own_fd = false; + // Destroy internal buffer if it exists + this->disable_buffer(); + return retval; +} + +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +// Convert int open mode to mode string +bool +gzfilebuf::open_mode(std::ios_base::openmode mode, + char* c_mode) const +{ + bool testb = mode & std::ios_base::binary; + bool testi = mode & std::ios_base::in; + bool testo = mode & std::ios_base::out; + bool testt = mode & std::ios_base::trunc; + bool testa = mode & std::ios_base::app; + + // Check for valid flag combinations - see [27.8.1.3.2] (Table 92) + // Original zfstream hardcoded the compression level to maximum here... + // Double the time for less than 1% size improvement seems + // excessive though - keeping it at the default level + // To change back, just append "9" to the next three mode strings + if (!testi && testo && !testt && !testa) + strcpy(c_mode, "w"); + if (!testi && testo && !testt && testa) + strcpy(c_mode, "a"); + if (!testi && testo && testt && !testa) + strcpy(c_mode, "w"); + if (testi && !testo && !testt && !testa) + strcpy(c_mode, "r"); + // No read/write mode yet +// if (testi && testo && !testt && !testa) +// strcpy(c_mode, "r+"); +// if (testi && testo && testt && !testa) +// strcpy(c_mode, "w+"); + + // Mode string should be empty for invalid combination of flags + if (strlen(c_mode) == 0) + return false; + if (testb) + strcat(c_mode, "b"); + return true; +} + +// Determine number of characters in internal get buffer +std::streamsize +gzfilebuf::showmanyc() +{ + // Calls to underflow will fail if file not opened for reading + if (!this->is_open() || !(io_mode & std::ios_base::in)) + return -1; + // Make sure get area is in use + if (this->gptr() && (this->gptr() < this->egptr())) + return std::streamsize(this->egptr() - this->gptr()); + else + return 0; +} + +// Fill get area from gzipped file +gzfilebuf::int_type +gzfilebuf::underflow() +{ + // If something is left in the get area by chance, return it + // (this shouldn't normally happen, as underflow is only supposed + // to be called when gptr >= egptr, but it serves as error check) + if (this->gptr() && (this->gptr() < this->egptr())) + return traits_type::to_int_type(*(this->gptr())); + + // If the file hasn't been opened for reading, produce error + if (!this->is_open() || !(io_mode & std::ios_base::in)) + return traits_type::eof(); + + // Attempt to fill internal buffer from gzipped file + // (buffer must be guaranteed to exist...) + int bytes_read = gzread(file, buffer, buffer_size); + // Indicates error or EOF + if (bytes_read <= 0) + { + // Reset get area + this->setg(buffer, buffer, buffer); + return traits_type::eof(); + } + // Make all bytes read from file available as get area + this->setg(buffer, buffer, buffer + bytes_read); + + // Return next character in get area + return traits_type::to_int_type(*(this->gptr())); +} + +// Write put area to gzipped file +gzfilebuf::int_type +gzfilebuf::overflow(int_type c) +{ + // Determine whether put area is in use + if (this->pbase()) + { + // Double-check pointer range + if (this->pptr() > this->epptr() || this->pptr() < this->pbase()) + return traits_type::eof(); + // Add extra character to buffer if not EOF + if (!traits_type::eq_int_type(c, traits_type::eof())) + { + *(this->pptr()) = traits_type::to_char_type(c); + this->pbump(1); + } + // Number of characters to write to file + int bytes_to_write = this->pptr() - this->pbase(); + // Overflow doesn't fail if nothing is to be written + if (bytes_to_write > 0) + { + // If the file hasn't been opened for writing, produce error + if (!this->is_open() || !(io_mode & std::ios_base::out)) + return traits_type::eof(); + // If gzipped file won't accept all bytes written to it, fail + if (gzwrite(file, this->pbase(), bytes_to_write) != bytes_to_write) + return traits_type::eof(); + // Reset next pointer to point to pbase on success + this->pbump(-bytes_to_write); + } + } + // Write extra character to file if not EOF + else if (!traits_type::eq_int_type(c, traits_type::eof())) + { + // If the file hasn't been opened for writing, produce error + if (!this->is_open() || !(io_mode & std::ios_base::out)) + return traits_type::eof(); + // Impromptu char buffer (allows "unbuffered" output) + char_type last_char = traits_type::to_char_type(c); + // If gzipped file won't accept this character, fail + if (gzwrite(file, &last_char, 1) != 1) + return traits_type::eof(); + } + + // If you got here, you have succeeded (even if c was EOF) + // The return value should therefore be non-EOF + if (traits_type::eq_int_type(c, traits_type::eof())) + return traits_type::not_eof(c); + else + return c; +} + +// Assign new buffer +std::streambuf* +gzfilebuf::setbuf(char_type* p, + std::streamsize n) +{ + // First make sure stuff is sync'ed, for safety + if (this->sync() == -1) + return NULL; + // If buffering is turned off on purpose via setbuf(0,0), still allocate one... + // "Unbuffered" only really refers to put [27.8.1.4.10], while get needs at + // least a buffer of size 1 (very inefficient though, therefore make it bigger?) + // This follows from [27.5.2.4.3]/12 (gptr needs to point at something, it seems) + if (!p || !n) + { + // Replace existing buffer (if any) with small internal buffer + this->disable_buffer(); + buffer = NULL; + buffer_size = 0; + own_buffer = true; + this->enable_buffer(); + } + else + { + // Replace existing buffer (if any) with external buffer + this->disable_buffer(); + buffer = p; + buffer_size = n; + own_buffer = false; + this->enable_buffer(); + } + return this; +} + +// Write put area to gzipped file (i.e. ensures that put area is empty) +int +gzfilebuf::sync() +{ + return traits_type::eq_int_type(this->overflow(), traits_type::eof()) ? -1 : 0; +} + +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +// Allocate internal buffer +void +gzfilebuf::enable_buffer() +{ + // If internal buffer required, allocate one + if (own_buffer && !buffer) + { + // Check for buffered vs. "unbuffered" + if (buffer_size > 0) + { + // Allocate internal buffer + buffer = new char_type[buffer_size]; + // Get area starts empty and will be expanded by underflow as need arises + this->setg(buffer, buffer, buffer); + // Setup entire internal buffer as put area. + // The one-past-end pointer actually points to the last element of the buffer, + // so that overflow(c) can safely add the extra character c to the sequence. + // These pointers remain in place for the duration of the buffer + this->setp(buffer, buffer + buffer_size - 1); + } + else + { + // Even in "unbuffered" case, (small?) get buffer is still required + buffer_size = SMALLBUFSIZE; + buffer = new char_type[buffer_size]; + this->setg(buffer, buffer, buffer); + // "Unbuffered" means no put buffer + this->setp(0, 0); + } + } + else + { + // If buffer already allocated, reset buffer pointers just to make sure no + // stale chars are lying around + this->setg(buffer, buffer, buffer); + this->setp(buffer, buffer + buffer_size - 1); + } +} + +// Destroy internal buffer +void +gzfilebuf::disable_buffer() +{ + // If internal buffer exists, deallocate it + if (own_buffer && buffer) + { + // Preserve unbuffered status by zeroing size + if (!this->pbase()) + buffer_size = 0; + delete[] buffer; + buffer = NULL; + this->setg(0, 0, 0); + this->setp(0, 0); + } + else + { + // Reset buffer pointers to initial state if external buffer exists + this->setg(buffer, buffer, buffer); + if (buffer) + this->setp(buffer, buffer + buffer_size - 1); + else + this->setp(0, 0); + } +} + +/*****************************************************************************/ + +// Default constructor initializes stream buffer +gzifstream::gzifstream() +: std::istream(NULL), sb() +{ this->init(&sb); } + +// Initialize stream buffer and open file +gzifstream::gzifstream(const char* name, + std::ios_base::openmode mode) +: std::istream(NULL), sb() +{ + this->init(&sb); + this->open(name, mode); +} + +// Initialize stream buffer and attach to file +gzifstream::gzifstream(int fd, + std::ios_base::openmode mode) +: std::istream(NULL), sb() +{ + this->init(&sb); + this->attach(fd, mode); +} + +// Open file and go into fail() state if unsuccessful +void +gzifstream::open(const char* name, + std::ios_base::openmode mode) +{ + if (!sb.open(name, mode | std::ios_base::in)) + this->setstate(std::ios_base::failbit); + else + this->clear(); +} + +// Attach to file and go into fail() state if unsuccessful +void +gzifstream::attach(int fd, + std::ios_base::openmode mode) +{ + if (!sb.attach(fd, mode | std::ios_base::in)) + this->setstate(std::ios_base::failbit); + else + this->clear(); +} + +// Close file +void +gzifstream::close() +{ + if (!sb.close()) + this->setstate(std::ios_base::failbit); +} + +/*****************************************************************************/ + +// Default constructor initializes stream buffer +gzofstream::gzofstream() +: std::ostream(NULL), sb() +{ this->init(&sb); } + +// Initialize stream buffer and open file +gzofstream::gzofstream(const char* name, + std::ios_base::openmode mode) +: std::ostream(NULL), sb() +{ + this->init(&sb); + this->open(name, mode); +} + +// Initialize stream buffer and attach to file +gzofstream::gzofstream(int fd, + std::ios_base::openmode mode) +: std::ostream(NULL), sb() +{ + this->init(&sb); + this->attach(fd, mode); +} + +// Open file and go into fail() state if unsuccessful +void +gzofstream::open(const char* name, + std::ios_base::openmode mode) +{ + if (!sb.open(name, mode | std::ios_base::out)) + this->setstate(std::ios_base::failbit); + else + this->clear(); +} + +// Attach to file and go into fail() state if unsuccessful +void +gzofstream::attach(int fd, + std::ios_base::openmode mode) +{ + if (!sb.attach(fd, mode | std::ios_base::out)) + this->setstate(std::ios_base::failbit); + else + this->clear(); +} + +// Close file +void +gzofstream::close() +{ + if (!sb.close()) + this->setstate(std::ios_base::failbit); +} diff --git a/ext/iostream3/zfstream.h b/ext/iostream3/zfstream.h new file mode 100644 index 000000000..8574479ae --- /dev/null +++ b/ext/iostream3/zfstream.h @@ -0,0 +1,466 @@ +/* + * A C++ I/O streams interface to the zlib gz* functions + * + * by Ludwig Schwardt <schwardt@sun.ac.za> + * original version by Kevin Ruland <kevin@rodin.wustl.edu> + * + * This version is standard-compliant and compatible with gcc 3.x. + */ + +#ifndef ZFSTREAM_H +#define ZFSTREAM_H + +#include <istream> // not iostream, since we don't need cin/cout +#include <ostream> +#include "zlib.h" + +/*****************************************************************************/ + +/** + * @brief Gzipped file stream buffer class. + * + * This class implements basic_filebuf for gzipped files. It doesn't yet support + * seeking (allowed by zlib but slow/limited), putback and read/write access + * (tricky). Otherwise, it attempts to be a drop-in replacement for the standard + * file streambuf. +*/ +class gzfilebuf : public std::streambuf +{ +public: + // Default constructor. + gzfilebuf(); + + // Destructor. + virtual + ~gzfilebuf(); + + /** + * @brief Set compression level and strategy on the fly. + * @param comp_level Compression level (see zlib.h for allowed values) + * @param comp_strategy Compression strategy (see zlib.h for allowed values) + * @return Z_OK on success, Z_STREAM_ERROR otherwise. + * + * Unfortunately, these parameters cannot be modified separately, as the + * previous zfstream version assumed. Since the strategy is seldom changed, + * it can default and setcompression(level) then becomes like the old + * setcompressionlevel(level). + */ + int + setcompression(int comp_level, + int comp_strategy = Z_DEFAULT_STRATEGY); + + /** + * @brief Check if file is open. + * @return True if file is open. + */ + bool + is_open() const { return (file != NULL); } + + /** + * @brief Open gzipped file. + * @param name File name. + * @param mode Open mode flags. + * @return @c this on success, NULL on failure. + */ + gzfilebuf* + open(const char* name, + std::ios_base::openmode mode); + + /** + * @brief Attach to already open gzipped file. + * @param fd File descriptor. + * @param mode Open mode flags. + * @return @c this on success, NULL on failure. + */ + gzfilebuf* + attach(int fd, + std::ios_base::openmode mode); + + /** + * @brief Close gzipped file. + * @return @c this on success, NULL on failure. + */ + gzfilebuf* + close(); + +protected: + /** + * @brief Convert ios open mode int to mode string used by zlib. + * @return True if valid mode flag combination. + */ + bool + open_mode(std::ios_base::openmode mode, + char* c_mode) const; + + /** + * @brief Number of characters available in stream buffer. + * @return Number of characters. + * + * This indicates number of characters in get area of stream buffer. + * These characters can be read without accessing the gzipped file. + */ + virtual std::streamsize + showmanyc(); + + /** + * @brief Fill get area from gzipped file. + * @return First character in get area on success, EOF on error. + * + * This actually reads characters from gzipped file to stream + * buffer. Always buffered. + */ + virtual int_type + underflow(); + + /** + * @brief Write put area to gzipped file. + * @param c Extra character to add to buffer contents. + * @return Non-EOF on success, EOF on error. + * + * This actually writes characters in stream buffer to + * gzipped file. With unbuffered output this is done one + * character at a time. + */ + virtual int_type + overflow(int_type c = traits_type::eof()); + + /** + * @brief Installs external stream buffer. + * @param p Pointer to char buffer. + * @param n Size of external buffer. + * @return @c this on success, NULL on failure. + * + * Call setbuf(0,0) to enable unbuffered output. + */ + virtual std::streambuf* + setbuf(char_type* p, + std::streamsize n); + + /** + * @brief Flush stream buffer to file. + * @return 0 on success, -1 on error. + * + * This calls underflow(EOF) to do the job. + */ + virtual int + sync(); + +// +// Some future enhancements +// +// virtual int_type uflow(); +// virtual int_type pbackfail(int_type c = traits_type::eof()); +// virtual pos_type +// seekoff(off_type off, +// std::ios_base::seekdir way, +// std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out); +// virtual pos_type +// seekpos(pos_type sp, +// std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out); + +private: + /** + * @brief Allocate internal buffer. + * + * This function is safe to call multiple times. It will ensure + * that a proper internal buffer exists if it is required. If the + * buffer already exists or is external, the buffer pointers will be + * reset to their original state. + */ + void + enable_buffer(); + + /** + * @brief Destroy internal buffer. + * + * This function is safe to call multiple times. It will ensure + * that the internal buffer is deallocated if it exists. In any + * case, it will also reset the buffer pointers. + */ + void + disable_buffer(); + + /** + * Underlying file pointer. + */ + gzFile file; + + /** + * Mode in which file was opened. + */ + std::ios_base::openmode io_mode; + + /** + * @brief True if this object owns file descriptor. + * + * This makes the class responsible for closing the file + * upon destruction. + */ + bool own_fd; + + /** + * @brief Stream buffer. + * + * For simplicity this remains allocated on the free store for the + * entire life span of the gzfilebuf object, unless replaced by setbuf. + */ + char_type* buffer; + + /** + * @brief Stream buffer size. + * + * Defaults to system default buffer size (typically 8192 bytes). + * Modified by setbuf. + */ + std::streamsize buffer_size; + + /** + * @brief True if this object owns stream buffer. + * + * This makes the class responsible for deleting the buffer + * upon destruction. + */ + bool own_buffer; +}; + +/*****************************************************************************/ + +/** + * @brief Gzipped file input stream class. + * + * This class implements ifstream for gzipped files. Seeking and putback + * is not supported yet. +*/ +class gzifstream : public std::istream +{ +public: + // Default constructor + gzifstream(); + + /** + * @brief Construct stream on gzipped file to be opened. + * @param name File name. + * @param mode Open mode flags (forced to contain ios::in). + */ + explicit + gzifstream(const char* name, + std::ios_base::openmode mode = std::ios_base::in); + + /** + * @brief Construct stream on already open gzipped file. + * @param fd File descriptor. + * @param mode Open mode flags (forced to contain ios::in). + */ + explicit + gzifstream(int fd, + std::ios_base::openmode mode = std::ios_base::in); + + /** + * Obtain underlying stream buffer. + */ + gzfilebuf* + rdbuf() const + { return const_cast<gzfilebuf*>(&sb); } + + /** + * @brief Check if file is open. + * @return True if file is open. + */ + bool + is_open() { return sb.is_open(); } + + /** + * @brief Open gzipped file. + * @param name File name. + * @param mode Open mode flags (forced to contain ios::in). + * + * Stream will be in state good() if file opens successfully; + * otherwise in state fail(). This differs from the behavior of + * ifstream, which never sets the state to good() and therefore + * won't allow you to reuse the stream for a second file unless + * you manually clear() the state. The choice is a matter of + * convenience. + */ + void + open(const char* name, + std::ios_base::openmode mode = std::ios_base::in); + + /** + * @brief Attach to already open gzipped file. + * @param fd File descriptor. + * @param mode Open mode flags (forced to contain ios::in). + * + * Stream will be in state good() if attach succeeded; otherwise + * in state fail(). + */ + void + attach(int fd, + std::ios_base::openmode mode = std::ios_base::in); + + /** + * @brief Close gzipped file. + * + * Stream will be in state fail() if close failed. + */ + void + close(); + +private: + /** + * Underlying stream buffer. + */ + gzfilebuf sb; +}; + +/*****************************************************************************/ + +/** + * @brief Gzipped file output stream class. + * + * This class implements ofstream for gzipped files. Seeking and putback + * is not supported yet. +*/ +class gzofstream : public std::ostream +{ +public: + // Default constructor + gzofstream(); + + /** + * @brief Construct stream on gzipped file to be opened. + * @param name File name. + * @param mode Open mode flags (forced to contain ios::out). + */ + explicit + gzofstream(const char* name, + std::ios_base::openmode mode = std::ios_base::out); + + /** + * @brief Construct stream on already open gzipped file. + * @param fd File descriptor. + * @param mode Open mode flags (forced to contain ios::out). + */ + explicit + gzofstream(int fd, + std::ios_base::openmode mode = std::ios_base::out); + + /** + * Obtain underlying stream buffer. + */ + gzfilebuf* + rdbuf() const + { return const_cast<gzfilebuf*>(&sb); } + + /** + * @brief Check if file is open. + * @return True if file is open. + */ + bool + is_open() { return sb.is_open(); } + + /** + * @brief Open gzipped file. + * @param name File name. + * @param mode Open mode flags (forced to contain ios::out). + * + * Stream will be in state good() if file opens successfully; + * otherwise in state fail(). This differs from the behavior of + * ofstream, which never sets the state to good() and therefore + * won't allow you to reuse the stream for a second file unless + * you manually clear() the state. The choice is a matter of + * convenience. + */ + void + open(const char* name, + std::ios_base::openmode mode = std::ios_base::out); + + /** + * @brief Attach to already open gzipped file. + * @param fd File descriptor. + * @param mode Open mode flags (forced to contain ios::out). + * + * Stream will be in state good() if attach succeeded; otherwise + * in state fail(). + */ + void + attach(int fd, + std::ios_base::openmode mode = std::ios_base::out); + + /** + * @brief Close gzipped file. + * + * Stream will be in state fail() if close failed. + */ + void + close(); + +private: + /** + * Underlying stream buffer. + */ + gzfilebuf sb; +}; + +/*****************************************************************************/ + +/** + * @brief Gzipped file output stream manipulator class. + * + * This class defines a two-argument manipulator for gzofstream. It is used + * as base for the setcompression(int,int) manipulator. +*/ +template<typename T1, typename T2> + class gzomanip2 + { + public: + // Allows insertor to peek at internals + template <typename Ta, typename Tb> + friend gzofstream& + operator<<(gzofstream&, + const gzomanip2<Ta,Tb>&); + + // Constructor + gzomanip2(gzofstream& (*f)(gzofstream&, T1, T2), + T1 v1, + T2 v2); + private: + // Underlying manipulator function + gzofstream& + (*func)(gzofstream&, T1, T2); + + // Arguments for manipulator function + T1 val1; + T2 val2; + }; + +/*****************************************************************************/ + +// Manipulator function thunks through to stream buffer +inline gzofstream& +setcompression(gzofstream &gzs, int l, int s = Z_DEFAULT_STRATEGY) +{ + (gzs.rdbuf())->setcompression(l, s); + return gzs; +} + +// Manipulator constructor stores arguments +template<typename T1, typename T2> + inline + gzomanip2<T1,T2>::gzomanip2(gzofstream &(*f)(gzofstream &, T1, T2), + T1 v1, + T2 v2) + : func(f), val1(v1), val2(v2) + { } + +// Insertor applies underlying manipulator function to stream +template<typename T1, typename T2> + inline gzofstream& + operator<<(gzofstream& s, const gzomanip2<T1,T2>& m) + { return (*m.func)(s, m.val1, m.val2); } + +// Insert this onto stream to simplify setting of compression level +inline gzomanip2<int,int> +setcompression(int l, int s = Z_DEFAULT_STRATEGY) +{ return gzomanip2<int,int>(&setcompression, l, s); } + +#endif // ZFSTREAM_H |