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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /media/libpng/pngrio.c | |
parent | Initial commit. (diff) | |
download | firefox-esr-upstream/115.8.0esr.tar.xz firefox-esr-upstream/115.8.0esr.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/libpng/pngrio.c')
-rw-r--r-- | media/libpng/pngrio.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/media/libpng/pngrio.c b/media/libpng/pngrio.c new file mode 100644 index 0000000000..7946358101 --- /dev/null +++ b/media/libpng/pngrio.c @@ -0,0 +1,120 @@ + +/* pngrio.c - functions for data input + * + * Copyright (c) 2018 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all input. Users who need + * special handling are expected to write a function that has the same + * arguments as this and performs a similar function, but that possibly + * has a different input method. Note that you shouldn't change this + * function, but rather write a replacement function and then make + * libpng use it at run time with png_set_read_fn(...). + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* Read the data from whatever input you are using. The default routine + * reads from a file pointer. Note that this routine sometimes gets called + * with very small lengths, so you should implement some kind of simple + * buffering if you are using unbuffered reads. This should never be asked + * to read more than 64K on a 16-bit machine. + */ +void /* PRIVATE */ +png_read_data(png_structrp png_ptr, png_bytep data, size_t length) +{ + png_debug1(4, "reading %d bytes", (int)length); + + if (png_ptr->read_data_fn != NULL) + (*(png_ptr->read_data_fn))(png_ptr, data, length); + + else + png_error(png_ptr, "Call to NULL read function"); +} + +#ifdef PNG_STDIO_SUPPORTED +/* This is the function that does the actual reading of data. If you are + * not reading from a standard C stream, you should create a replacement + * read_data function and use it at run time with png_set_read_fn(), rather + * than changing the library. + */ +void PNGCBAPI +png_default_read_data(png_structp png_ptr, png_bytep data, size_t length) +{ + size_t check; + + if (png_ptr == NULL) + return; + + /* fread() returns 0 on error, so it is OK to store this in a size_t + * instead of an int, which is what fread() actually returns. + */ + check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr)); + + if (check != length) + png_error(png_ptr, "Read Error"); +} +#endif + +/* This function allows the application to supply a new input function + * for libpng if standard C streams aren't being used. + * + * This function takes as its arguments: + * + * png_ptr - pointer to a png input data structure + * + * io_ptr - pointer to user supplied structure containing info about + * the input functions. May be NULL. + * + * read_data_fn - pointer to a new input function that takes as its + * arguments a pointer to a png_struct, a pointer to + * a location where input data can be stored, and a 32-bit + * unsigned int that is the number of bytes to be read. + * To exit and output any fatal error messages the new write + * function should call png_error(png_ptr, "Error msg"). + * May be NULL, in which case libpng's default function will + * be used. + */ +void PNGAPI +png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = io_ptr; + +#ifdef PNG_STDIO_SUPPORTED + if (read_data_fn != NULL) + png_ptr->read_data_fn = read_data_fn; + + else + png_ptr->read_data_fn = png_default_read_data; +#else + png_ptr->read_data_fn = read_data_fn; +#endif + +#ifdef PNG_WRITE_SUPPORTED + /* It is an error to write to a read device */ + if (png_ptr->write_data_fn != NULL) + { + png_ptr->write_data_fn = NULL; + png_warning(png_ptr, + "Can't set both read_data_fn and write_data_fn in the" + " same structure"); + } +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->output_flush_fn = NULL; +#endif +} +#endif /* READ */ |