The Tor Browser / file comparison
comparison: media/libpng/pngrio.c
media/libpng/pngrio.c
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
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| -1:000000000000 | 0:df6b8c9f9dd2 |
|---|---|
| 1 | |
| 2 /* pngrio.c - functions for data input | |
| 3 * | |
| 4 * Last changed in libpng 1.6.9 [February 6, 2014] | |
| 5 * Copyright (c) 1998-2014 Glenn Randers-Pehrson | |
| 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) | |
| 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) | |
| 8 * | |
| 9 * This code is released under the libpng license. | |
| 10 * For conditions of distribution and use, see the disclaimer | |
| 11 * and license in png.h | |
| 12 * | |
| 13 * This file provides a location for all input. Users who need | |
| 14 * special handling are expected to write a function that has the same | |
| 15 * arguments as this and performs a similar function, but that possibly | |
| 16 * has a different input method. Note that you shouldn't change this | |
| 17 * function, but rather write a replacement function and then make | |
| 18 * libpng use it at run time with png_set_read_fn(...). | |
| 19 */ | |
| 20 | |
| 21 #include "pngpriv.h" | |
| 22 | |
| 23 #ifdef PNG_READ_SUPPORTED | |
| 24 | |
| 25 /* Read the data from whatever input you are using. The default routine | |
| 26 * reads from a file pointer. Note that this routine sometimes gets called | |
| 27 * with very small lengths, so you should implement some kind of simple | |
| 28 * buffering if you are using unbuffered reads. This should never be asked | |
| 29 * to read more then 64K on a 16 bit machine. | |
| 30 */ | |
| 31 void /* PRIVATE */ | |
| 32 png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length) | |
| 33 { | |
| 34 png_debug1(4, "reading %d bytes", (int)length); | |
| 35 | |
| 36 if (png_ptr->read_data_fn != NULL) | |
| 37 (*(png_ptr->read_data_fn))(png_ptr, data, length); | |
| 38 | |
| 39 else | |
| 40 png_error(png_ptr, "Call to NULL read function"); | |
| 41 } | |
| 42 | |
| 43 #ifdef PNG_STDIO_SUPPORTED | |
| 44 /* This is the function that does the actual reading of data. If you are | |
| 45 * not reading from a standard C stream, you should create a replacement | |
| 46 * read_data function and use it at run time with png_set_read_fn(), rather | |
| 47 * than changing the library. | |
| 48 */ | |
| 49 void PNGCBAPI | |
| 50 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) | |
| 51 { | |
| 52 png_size_t check; | |
| 53 | |
| 54 if (png_ptr == NULL) | |
| 55 return; | |
| 56 | |
| 57 /* fread() returns 0 on error, so it is OK to store this in a png_size_t | |
| 58 * instead of an int, which is what fread() actually returns. | |
| 59 */ | |
| 60 check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr)); | |
| 61 | |
| 62 if (check != length) | |
| 63 png_error(png_ptr, "Read Error"); | |
| 64 } | |
| 65 #endif | |
| 66 | |
| 67 /* This function allows the application to supply a new input function | |
| 68 * for libpng if standard C streams aren't being used. | |
| 69 * | |
| 70 * This function takes as its arguments: | |
| 71 * | |
| 72 * png_ptr - pointer to a png input data structure | |
| 73 * | |
| 74 * io_ptr - pointer to user supplied structure containing info about | |
| 75 * the input functions. May be NULL. | |
| 76 * | |
| 77 * read_data_fn - pointer to a new input function that takes as its | |
| 78 * arguments a pointer to a png_struct, a pointer to | |
| 79 * a location where input data can be stored, and a 32-bit | |
| 80 * unsigned int that is the number of bytes to be read. | |
| 81 * To exit and output any fatal error messages the new write | |
| 82 * function should call png_error(png_ptr, "Error msg"). | |
| 83 * May be NULL, in which case libpng's default function will | |
| 84 * be used. | |
| 85 */ | |
| 86 void PNGAPI | |
| 87 png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr, | |
| 88 png_rw_ptr read_data_fn) | |
| 89 { | |
| 90 if (png_ptr == NULL) | |
| 91 return; | |
| 92 | |
| 93 png_ptr->io_ptr = io_ptr; | |
| 94 | |
| 95 #ifdef PNG_STDIO_SUPPORTED | |
| 96 if (read_data_fn != NULL) | |
| 97 png_ptr->read_data_fn = read_data_fn; | |
| 98 | |
| 99 else | |
| 100 png_ptr->read_data_fn = png_default_read_data; | |
| 101 #else | |
| 102 png_ptr->read_data_fn = read_data_fn; | |
| 103 #endif | |
| 104 | |
| 105 #ifdef PNG_WRITE_SUPPORTED | |
| 106 /* It is an error to write to a read device */ | |
| 107 if (png_ptr->write_data_fn != NULL) | |
| 108 { | |
| 109 png_ptr->write_data_fn = NULL; | |
| 110 png_warning(png_ptr, | |
| 111 "Can't set both read_data_fn and write_data_fn in the" | |
| 112 " same structure"); | |
| 113 } | |
| 114 #endif | |
| 115 | |
| 116 #ifdef PNG_WRITE_FLUSH_SUPPORTED | |
| 117 png_ptr->output_flush_fn = NULL; | |
| 118 #endif | |
| 119 } | |
| 120 #endif /* PNG_READ_SUPPORTED */ |
