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Diffstat (limited to 'gr-blocks/lib/file_source_impl.cc')
| -rw-r--r-- | gr-blocks/lib/file_source_impl.cc | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/gr-blocks/lib/file_source_impl.cc b/gr-blocks/lib/file_source_impl.cc new file mode 100644 index 000000000..ed1f50c43 --- /dev/null +++ b/gr-blocks/lib/file_source_impl.cc @@ -0,0 +1,188 @@ +/* -*- c++ -*- */ +/* + * Copyright 2012 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3, or (at your option) + * any later version. + * + * GNU Radio is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "file_source_impl.h" +#include <gr_io_signature.h> +#include <cstdio> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <stdexcept> +#include <stdio.h> + +// win32 (mingw/msvc) specific +#ifdef HAVE_IO_H +#include <io.h> +#endif +#ifdef O_BINARY +#define OUR_O_BINARY O_BINARY +#else +#define OUR_O_BINARY 0 +#endif +// should be handled via configure +#ifdef O_LARGEFILE +#define OUR_O_LARGEFILE O_LARGEFILE +#else +#define OUR_O_LARGEFILE 0 +#endif + +namespace gr { + namespace blocks { + + file_source::sptr file_source::make(size_t itemsize, const char *filename, bool repeat) + { + return gnuradio::get_initial_sptr + (new file_source_impl(itemsize, filename, repeat)); + } + + file_source_impl::file_source_impl(size_t itemsize, const char *filename, bool repeat) + : gr_sync_block("file_source", + gr_make_io_signature(0, 0, 0), + gr_make_io_signature(1, 1, itemsize)), + d_itemsize(itemsize), d_fp(0), d_new_fp(0), d_repeat(repeat), + d_updated(false) + { + open(filename, repeat); + } + + file_source_impl::~file_source_impl() + { + fclose ((FILE*)d_fp); + } + + bool + file_source_impl::seek(long seek_point, int whence) + { + return fseek((FILE*)d_fp, seek_point *d_itemsize, whence) == 0; + } + + + void + file_source_impl::open(const char *filename, bool repeat) + { + // obtain exclusive access for duration of this function + boost::mutex::scoped_lock lock(fp_mutex); + + int fd; + + // we use "open" to use to the O_LARGEFILE flag + if((fd = ::open(filename, O_RDONLY | OUR_O_LARGEFILE | OUR_O_BINARY)) < 0) { + perror(filename); + throw std::runtime_error("can't open file"); + } + + if(d_new_fp) { + fclose(d_new_fp); + d_new_fp = 0; + } + + if((d_new_fp = fdopen (fd, "rb")) == NULL) { + perror(filename); + ::close(fd); // don't leak file descriptor if fdopen fails + throw std::runtime_error("can't open file"); + } + + d_updated = true; + d_repeat = repeat; + } + + void + file_source_impl::close() + { + // obtain exclusive access for duration of this function + boost::mutex::scoped_lock lock(fp_mutex); + + if(d_new_fp != NULL) { + fclose(d_new_fp); + d_new_fp = NULL; + } + d_updated = true; + } + + void + file_source_impl::do_update() + { + if(d_updated) { + boost::mutex::scoped_lock lock(fp_mutex); // hold while in scope + + if(d_fp) + fclose(d_fp); + + d_fp = d_new_fp; // install new file pointer + d_new_fp = 0; + d_updated = false; + } + } + + int + file_source_impl::work(int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) + { + char *o = (char*)output_items[0]; + int i; + int size = noutput_items; + + do_update(); // update d_fp is reqd + if(d_fp == NULL) + throw std::runtime_error("work with file not open"); + + boost::mutex::scoped_lock lock(fp_mutex); // hold for the rest of this function + while(size) { + i = fread(o, d_itemsize, size, (FILE*)d_fp); + + size -= i; + o += i * d_itemsize; + + if(size == 0) // done + break; + + if(i > 0) // short read, try again + continue; + + // We got a zero from fread. This is either EOF or error. In + // any event, if we're in repeat mode, seek back to the beginning + // of the file and try again, else break + if(!d_repeat) + break; + + if(fseek ((FILE *) d_fp, 0, SEEK_SET) == -1) { + fprintf(stderr, "[%s] fseek failed\n", __FILE__); + exit(-1); + } + } + + if(size > 0) { // EOF or error + if(size == noutput_items) // we didn't read anything; say we're done + return -1; + return noutput_items - size; // else return partial result + } + + return noutput_items; + } + + } /* namespace blocks */ +} /* namespace gr */ |