I hereby relicense all my work on Sortix under the ISC license as below. All Sortix contributions by other people are already under this license, are not substantial enough to be copyrightable, or have been removed. All imported code from other projects is compatible with this license. All GPL licensed code from other projects had previously been removed. Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors. Permission to use, copy, modify, and 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 THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
119 lines
3.2 KiB
C
119 lines
3.2 KiB
C
/*
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* Copyright (c) 2015 Jonas 'Sortie' Termansen.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* libc/stdio/open_memstream.c
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* Open a memory stream.
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*/
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#include <sys/types.h>
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#include <errno.h>
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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struct memstream
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{
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char** string_out;
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size_t* used_out;
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char* string;
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size_t offset;
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size_t used;
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size_t size;
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};
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static ssize_t memstream_write(void* ms_ptr, const void* src, size_t count)
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{
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struct memstream* ms = (struct memstream*) ms_ptr;
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if ( (size_t) SSIZE_MAX < count )
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count = SSIZE_MAX;
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if ( ms->offset == SIZE_MAX && 1 <= count )
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return errno = EOVERFLOW, -1;
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if ( (size_t) SSIZE_MAX - ms->offset < count )
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count = SIZE_MAX - ms->offset;
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size_t required_size = ms->offset + count;
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if ( ms->size < required_size )
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{
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// TODO: Multiplication overflow.
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size_t new_size = 2 * ms->size;
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if ( new_size < 16 )
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new_size = 16;
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if ( new_size < required_size )
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new_size = required_size;
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if ( SIZE_MAX - new_size < 1 )
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return errno = EOVERFLOW, -1;
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char* new_string = (char*) realloc(ms->string, new_size + 1);
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if ( !new_string )
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return -1;
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ms->string = new_string;
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ms->size = new_size;
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}
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memcpy(ms->string + ms->offset, src, count);
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ms->offset += count;
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if ( ms->used < required_size )
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{
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ms->used = required_size;
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ms->string[ms->used] = '\0';
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}
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*ms->string_out = ms->string;
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*ms->used_out = ms->used;
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return count;
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}
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static off_t memstream_seek(void* ms_ptr, off_t offset, int whence)
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{
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struct memstream* ms = (struct memstream*) ms_ptr;
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off_t base;
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switch ( whence )
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{
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case SEEK_SET: base = 0; break;
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case SEEK_CUR: base = (off_t) ms->offset; break;
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case SEEK_END: base = (off_t) ms->used; break;
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default: return errno = EINVAL, -1;
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}
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if ( offset < -base || base - SSIZE_MAX < offset )
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return errno = EOVERFLOW, -1;
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return (off_t) (ms->offset = (size_t) (base + offset));
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}
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FILE* open_memstream(char** string_out, size_t* used_out)
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{
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char* string = (char*) malloc(1);
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if ( !string )
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return NULL;
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string[0] = '\0';
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struct memstream* ms = (struct memstream*) malloc(sizeof(struct memstream));
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if ( !ms )
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return free(string), (FILE*) NULL;
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FILE* fp = fnewfile();
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if ( !fp )
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return free(ms), free(string), (FILE*) NULL;
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ms->string_out = string_out;
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ms->used_out = used_out;
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ms->string= string;
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ms->offset = 0;
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ms->used = 0;
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ms->size = 0;
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fp->flags |= _FILE_WRITABLE;
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fp->fd = -1;
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fp->user = ms;
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fp->write_func = memstream_write;
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fp->seek_func = memstream_seek;
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*string_out = ms->string;
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*used_out = ms->used;
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return fp;
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}
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