[trunk] support seeking in files larger than 2 GB

This commit is contained in:
Julien Malik 2011-11-24 15:30:09 +00:00
parent 20c05a3add
commit c974cb1b8e
3 changed files with 23 additions and 1 deletions

View File

@ -5,6 +5,9 @@ What's New for OpenJPEG
! : changed
+ : added
November 24, 2011
* [jmalik] support seeking in files larger than 2 GB
November 21, 2011
* [mickael] WIP: fix bug with windows platform and j2k_dump

View File

@ -165,7 +165,25 @@ OPJ_SIZE_T opj_skip_from_file (OPJ_SIZE_T p_nb_bytes, FILE * p_user_data)
opj_bool opj_seek_from_file (OPJ_SIZE_T p_nb_bytes, FILE * p_user_data)
{
if (fseek(p_user_data,p_nb_bytes,SEEK_SET)) {
/*
* p_nb_bytes is 'OPJ_SIZE_T' but fseek takes a 'signed long'
*
* As such, fseek can seek to a maximum of 2^31-1 bytes (2 GB)
* To support seeking in files between 2 GB and 4 GB :
* - first, do a seek with the max supported by fseek
* - secondly, seek of the remaining bytes
*/
if (p_nb_bytes > LONG_MAX) {
if (fseek(p_user_data,LONG_MAX,SEEK_SET)) {
return EXIT_FAILURE;
}
p_nb_bytes -= LONG_MAX;
if (fseek(p_user_data,p_nb_bytes,SEEK_CUR)) {
return EXIT_FAILURE;
}
}
else if (fseek(p_user_data,p_nb_bytes,SEEK_SET)) {
return EXIT_FAILURE;
}

View File

@ -41,6 +41,7 @@
#include <stdarg.h>
#include <ctype.h>
#include <assert.h>
#include <limits.h>
/*
==========================================================