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614313f12f
Since curl_off_t is always 64 bit these days, we can simplify and avoid using some macros. Closes #17498
95 lines
3.3 KiB
C
95 lines
3.3 KiB
C
/***************************************************************************
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* _ _ ____ _
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* Project ___| | | | _ \| |
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* / __| | | | |_) | |
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* | (__| |_| | _ <| |___
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* \___|\___/|_| \_\_____|
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*
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* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
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*
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* This software is licensed as described in the file COPYING, which
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* you should have received as part of this distribution. The terms
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* are also available at https://curl.se/docs/copyright.html.
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*
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* You may opt to use, copy, modify, merge, publish, distribute and/or sell
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* copies of the Software, and permit persons to whom the Software is
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* furnished to do so, under the terms of the COPYING file.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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* SPDX-License-Identifier: curl
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*
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***************************************************************************/
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#include "tool_setup.h"
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#include <curlx.h>
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#include "tool_cfgable.h"
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#include "tool_operate.h"
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#include "tool_cb_see.h"
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#include <memdebug.h> /* keep this as LAST include */
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/*
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** callback for CURLOPT_SEEKFUNCTION
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**
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** Notice that this is not supposed to return the resulting offset. This
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** shall only return CURL_SEEKFUNC_* return codes.
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*/
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int tool_seek_cb(void *userdata, curl_off_t offset, int whence)
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{
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struct per_transfer *per = userdata;
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#if (SIZEOF_CURL_OFF_T > SIZEOF_OFF_T) && !defined(USE_WIN32_LARGE_FILES)
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/* OUR_MAX_SEEK_L has 'long' data type, OUR_MAX_SEEK_O has 'curl_off_t,
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both represent the same value. Maximum offset used here when we lseek
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using a 'long' data type offset */
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#define OUR_MAX_SEEK_L 2147483647L - 1L
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#define OUR_MAX_SEEK_O 0x7FFFFFFF - 0x1
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/* The offset check following here is only interesting if curl_off_t is
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larger than off_t and we are not using the Win32 large file support
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macros that provide the support to do 64-bit seeks correctly */
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if(offset > OUR_MAX_SEEK_O) {
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/* Some precaution code to work around problems with different data sizes
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to allow seeking >32-bit even if off_t is 32-bit. Should be very rare
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and is really valid on weirdo-systems. */
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curl_off_t left = offset;
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if(whence != SEEK_SET)
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/* this code path does not support other types */
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return CURL_SEEKFUNC_FAIL;
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if(LSEEK_ERROR == lseek(per->infd, 0, SEEK_SET))
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/* could not rewind to beginning */
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return CURL_SEEKFUNC_FAIL;
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while(left) {
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long step = (left > OUR_MAX_SEEK_O) ? OUR_MAX_SEEK_L : (long)left;
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if(LSEEK_ERROR == lseek(per->infd, step, SEEK_CUR))
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/* could not seek forwards the desired amount */
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return CURL_SEEKFUNC_FAIL;
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left -= step;
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}
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return CURL_SEEKFUNC_OK;
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}
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#endif
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#if defined(__AMIGA__) || defined(__MINGW32CE__)
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if(LSEEK_ERROR == lseek(per->infd, (off_t)offset, whence))
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#else
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if(LSEEK_ERROR == lseek(per->infd, offset, whence))
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#endif
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/* could not rewind, the reason is in errno but errno is just not portable
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enough and we do not actually care that much why we failed. We will let
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libcurl know that it may try other means if it wants to. */
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return CURL_SEEKFUNC_CANTSEEK;
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return CURL_SEEKFUNC_OK;
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}
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