The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 1 | |
| 2 | /* pngwio.c - functions for data output |
| 3 | * |
Sireesh Tripurari | b478e66 | 2014-05-09 15:15:10 +0530 | [diff] [blame] | 4 | * Last changed in libpng 1.6.9 [February 6, 2014] |
| 5 | * Copyright (c) 1998-2014 Glenn Randers-Pehrson |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 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 | * |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 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 | * |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 13 | * This file provides a location for all output. Users who need |
| 14 | * special handling are expected to write functions that have the same |
| 15 | * arguments as these and perform similar functions, but that possibly |
| 16 | * use different output methods. Note that you shouldn't change these |
| 17 | * functions, but rather write replacement functions and then change |
| 18 | * them at run time with png_set_write_fn(...). |
| 19 | */ |
| 20 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 21 | #include "pngpriv.h" |
| 22 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 23 | #ifdef PNG_WRITE_SUPPORTED |
| 24 | |
| 25 | /* Write the data to whatever output you are using. The default routine |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 26 | * writes to 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 writes. This should never be asked |
| 29 | * to write more than 64K on a 16 bit machine. |
| 30 | */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 31 | |
| 32 | void /* PRIVATE */ |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 33 | png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 34 | { |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 35 | /* NOTE: write_data_fn must not change the buffer! */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 36 | if (png_ptr->write_data_fn != NULL ) |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 37 | (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data), |
| 38 | length); |
| 39 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 40 | else |
| 41 | png_error(png_ptr, "Call to NULL write function"); |
| 42 | } |
| 43 | |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 44 | #ifdef PNG_STDIO_SUPPORTED |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 45 | /* This is the function that does the actual writing of data. If you are |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 46 | * not writing to a standard C stream, you should create a replacement |
| 47 | * write_data function and use it at run time with png_set_write_fn(), rather |
| 48 | * than changing the library. |
| 49 | */ |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 50 | void PNGCBAPI |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 51 | png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) |
| 52 | { |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 53 | png_size_t check; |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 54 | |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 55 | if (png_ptr == NULL) |
| 56 | return; |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 57 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 58 | check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 59 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 60 | if (check != length) |
| 61 | png_error(png_ptr, "Write Error"); |
| 62 | } |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 63 | #endif |
| 64 | |
| 65 | /* This function is called to output any data pending writing (normally |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 66 | * to disk). After png_flush is called, there should be no data pending |
| 67 | * writing in any buffers. |
| 68 | */ |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 69 | #ifdef PNG_WRITE_FLUSH_SUPPORTED |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 70 | void /* PRIVATE */ |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 71 | png_flush(png_structrp png_ptr) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 72 | { |
| 73 | if (png_ptr->output_flush_fn != NULL) |
| 74 | (*(png_ptr->output_flush_fn))(png_ptr); |
| 75 | } |
| 76 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 77 | # ifdef PNG_STDIO_SUPPORTED |
| 78 | void PNGCBAPI |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 79 | png_default_flush(png_structp png_ptr) |
| 80 | { |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 81 | png_FILE_p io_ptr; |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 82 | |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 83 | if (png_ptr == NULL) |
| 84 | return; |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 85 | |
| 86 | io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr)); |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 87 | fflush(io_ptr); |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 88 | } |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 89 | # endif |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 90 | #endif |
| 91 | |
| 92 | /* This function allows the application to supply new output functions for |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 93 | * libpng if standard C streams aren't being used. |
| 94 | * |
| 95 | * This function takes as its arguments: |
| 96 | * png_ptr - pointer to a png output data structure |
| 97 | * io_ptr - pointer to user supplied structure containing info about |
| 98 | * the output functions. May be NULL. |
| 99 | * write_data_fn - pointer to a new output function that takes as its |
| 100 | * arguments a pointer to a png_struct, a pointer to |
| 101 | * data to be written, and a 32-bit unsigned int that is |
| 102 | * the number of bytes to be written. The new write |
| 103 | * function should call png_error(png_ptr, "Error msg") |
| 104 | * to exit and output any fatal error messages. May be |
| 105 | * NULL, in which case libpng's default function will |
| 106 | * be used. |
| 107 | * flush_data_fn - pointer to a new flush function that takes as its |
| 108 | * arguments a pointer to a png_struct. After a call to |
| 109 | * the flush function, there should be no data in any buffers |
| 110 | * or pending transmission. If the output method doesn't do |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 111 | * any buffering of output, a function prototype must still be |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 112 | * supplied although it doesn't have to do anything. If |
| 113 | * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile |
| 114 | * time, output_flush_fn will be ignored, although it must be |
| 115 | * supplied for compatibility. May be NULL, in which case |
| 116 | * libpng's default function will be used, if |
| 117 | * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not |
| 118 | * a good idea if io_ptr does not point to a standard |
| 119 | * *FILE structure. |
| 120 | */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 121 | void PNGAPI |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 122 | png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr, |
| 123 | png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 124 | { |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 125 | if (png_ptr == NULL) |
| 126 | return; |
| 127 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 128 | png_ptr->io_ptr = io_ptr; |
| 129 | |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 130 | #ifdef PNG_STDIO_SUPPORTED |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 131 | if (write_data_fn != NULL) |
| 132 | png_ptr->write_data_fn = write_data_fn; |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 133 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 134 | else |
| 135 | png_ptr->write_data_fn = png_default_write_data; |
| 136 | #else |
| 137 | png_ptr->write_data_fn = write_data_fn; |
| 138 | #endif |
| 139 | |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 140 | #ifdef PNG_WRITE_FLUSH_SUPPORTED |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 141 | # ifdef PNG_STDIO_SUPPORTED |
| 142 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 143 | if (output_flush_fn != NULL) |
| 144 | png_ptr->output_flush_fn = output_flush_fn; |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 145 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 146 | else |
| 147 | png_ptr->output_flush_fn = png_default_flush; |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 148 | |
| 149 | # else |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 150 | png_ptr->output_flush_fn = output_flush_fn; |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 151 | # endif |
Sireesh Tripurari | b478e66 | 2014-05-09 15:15:10 +0530 | [diff] [blame] | 152 | #else |
| 153 | PNG_UNUSED(output_flush_fn) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 154 | #endif /* PNG_WRITE_FLUSH_SUPPORTED */ |
| 155 | |
Sireesh Tripurari | b478e66 | 2014-05-09 15:15:10 +0530 | [diff] [blame] | 156 | #ifdef PNG_READ_SUPPORTED |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 157 | /* It is an error to read while writing a png file */ |
| 158 | if (png_ptr->read_data_fn != NULL) |
| 159 | { |
| 160 | png_ptr->read_data_fn = NULL; |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 161 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 162 | png_warning(png_ptr, |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame] | 163 | "Can't set both read_data_fn and write_data_fn in the" |
| 164 | " same structure"); |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 165 | } |
Sireesh Tripurari | b478e66 | 2014-05-09 15:15:10 +0530 | [diff] [blame] | 166 | #endif |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 167 | } |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 168 | #endif /* PNG_WRITE_SUPPORTED */ |