| OLD | NEW |
| 1 | 1 |
| 2 /* pngrio.c - functions for data input | 2 /* pngrio.c - functions for data input |
| 3 * | 3 * |
| 4 * Last changed in libpng 1.2.43 [February 25, 2010] | 4 * Last changed in libpng 1.6.17 [March 26, 2015] |
| 5 * Copyright (c) 1998-2010 Glenn Randers-Pehrson | 5 * Copyright (c) 1998-2015 Glenn Randers-Pehrson |
| 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) | 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) | 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
| 8 * | 8 * |
| 9 * This code is released under the libpng license. | 9 * This code is released under the libpng license. |
| 10 * For conditions of distribution and use, see the disclaimer | 10 * For conditions of distribution and use, see the disclaimer |
| 11 * and license in png.h | 11 * and license in png.h |
| 12 * | 12 * |
| 13 * This file provides a location for all input. Users who need | 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 | 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 | 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 | 16 * has a different input method. Note that you shouldn't change this |
| 17 * function, but rather write a replacement function and then make | 17 * function, but rather write a replacement function and then make |
| 18 * libpng use it at run time with png_set_read_fn(...). | 18 * libpng use it at run time with png_set_read_fn(...). |
| 19 */ | 19 */ |
| 20 | 20 |
| 21 #define PNG_INTERNAL | 21 #include "pngpriv.h" |
| 22 #define PNG_NO_PEDANTIC_WARNINGS | 22 |
| 23 #include "png.h" | |
| 24 #ifdef PNG_READ_SUPPORTED | 23 #ifdef PNG_READ_SUPPORTED |
| 25 | 24 |
| 26 /* Read the data from whatever input you are using. The default routine | 25 /* Read the data from whatever input you are using. The default routine |
| 27 * reads from a file pointer. Note that this routine sometimes gets called | 26 * reads from a file pointer. Note that this routine sometimes gets called |
| 28 * with very small lengths, so you should implement some kind of simple | 27 * with very small lengths, so you should implement some kind of simple |
| 29 * buffering if you are using unbuffered reads. This should never be asked | 28 * buffering if you are using unbuffered reads. This should never be asked |
| 30 * to read more then 64K on a 16 bit machine. | 29 * to read more than 64K on a 16-bit machine. |
| 31 */ | 30 */ |
| 32 void /* PRIVATE */ | 31 void /* PRIVATE */ |
| 33 png_read_data(png_structp png_ptr, png_bytep data, png_size_t length) | 32 png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length) |
| 34 { | 33 { |
| 35 png_debug1(4, "reading %d bytes", (int)length); | 34 png_debug1(4, "reading %d bytes", (int)length); |
| 36 | 35 |
| 37 if (png_ptr->read_data_fn != NULL) | 36 if (png_ptr->read_data_fn != NULL) |
| 38 (*(png_ptr->read_data_fn))(png_ptr, data, length); | 37 (*(png_ptr->read_data_fn))(png_ptr, data, length); |
| 38 |
| 39 else | 39 else |
| 40 png_error(png_ptr, "Call to NULL read function"); | 40 png_error(png_ptr, "Call to NULL read function"); |
| 41 } | 41 } |
| 42 | 42 |
| 43 #ifdef PNG_STDIO_SUPPORTED | 43 #ifdef PNG_STDIO_SUPPORTED |
| 44 /* This is the function that does the actual reading of data. If you are | 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 | 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 | 46 * read_data function and use it at run time with png_set_read_fn(), rather |
| 47 * than changing the library. | 47 * than changing the library. |
| 48 */ | 48 */ |
| 49 #ifndef USE_FAR_KEYWORD | 49 void PNGCBAPI |
| 50 void PNGAPI | |
| 51 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) | 50 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) |
| 52 { | 51 { |
| 53 png_size_t check; | 52 png_size_t check; |
| 54 | 53 |
| 55 if (png_ptr == NULL) | 54 if (png_ptr == NULL) |
| 56 return; | 55 return; |
| 56 |
| 57 /* fread() returns 0 on error, so it is OK to store this in a png_size_t | 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. | 58 * instead of an int, which is what fread() actually returns. |
| 59 */ | 59 */ |
| 60 #ifdef _WIN32_WCE | 60 check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr)); |
| 61 if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) ) | |
| 62 check = 0; | |
| 63 #else | |
| 64 check = (png_size_t)fread(data, (png_size_t)1, length, | |
| 65 (png_FILE_p)png_ptr->io_ptr); | |
| 66 #endif | |
| 67 | 61 |
| 68 if (check != length) | 62 if (check != length) |
| 69 png_error(png_ptr, "Read Error"); | 63 png_error(png_ptr, "Read Error"); |
| 70 } | 64 } |
| 71 #else | |
| 72 /* This is the model-independent version. Since the standard I/O library | |
| 73 can't handle far buffers in the medium and small models, we have to copy | |
| 74 the data. | |
| 75 */ | |
| 76 | |
| 77 #define NEAR_BUF_SIZE 1024 | |
| 78 #define MIN(a,b) (a <= b ? a : b) | |
| 79 | |
| 80 static void PNGAPI | |
| 81 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) | |
| 82 { | |
| 83 int check; | |
| 84 png_byte *n_data; | |
| 85 png_FILE_p io_ptr; | |
| 86 | |
| 87 if (png_ptr == NULL) | |
| 88 return; | |
| 89 /* Check if data really is near. If so, use usual code. */ | |
| 90 n_data = (png_byte *)CVT_PTR_NOCHECK(data); | |
| 91 io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr); | |
| 92 if ((png_bytep)n_data == data) | |
| 93 { | |
| 94 #ifdef _WIN32_WCE | |
| 95 if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, | |
| 96 NULL) ) | |
| 97 check = 0; | |
| 98 #else | |
| 99 check = fread(n_data, 1, length, io_ptr); | |
| 100 #endif | |
| 101 } | |
| 102 else | |
| 103 { | |
| 104 png_byte buf[NEAR_BUF_SIZE]; | |
| 105 png_size_t read, remaining, err; | |
| 106 check = 0; | |
| 107 remaining = length; | |
| 108 do | |
| 109 { | |
| 110 read = MIN(NEAR_BUF_SIZE, remaining); | |
| 111 #ifdef _WIN32_WCE | |
| 112 if ( !ReadFile((HANDLE)(io_ptr), buf, read, &err, NULL) ) | |
| 113 err = 0; | |
| 114 #else | |
| 115 err = fread(buf, (png_size_t)1, read, io_ptr); | |
| 116 #endif | |
| 117 png_memcpy(data, buf, read); /* copy far buffer to near buffer */ | |
| 118 if (err != read) | |
| 119 break; | |
| 120 else | |
| 121 check += err; | |
| 122 data += read; | |
| 123 remaining -= read; | |
| 124 } | |
| 125 while (remaining != 0); | |
| 126 } | |
| 127 if ((png_uint_32)check != (png_uint_32)length) | |
| 128 png_error(png_ptr, "read Error"); | |
| 129 } | |
| 130 #endif | |
| 131 #endif | 65 #endif |
| 132 | 66 |
| 133 /* This function allows the application to supply a new input function | 67 /* This function allows the application to supply a new input function |
| 134 * for libpng if standard C streams aren't being used. | 68 * for libpng if standard C streams aren't being used. |
| 135 * | 69 * |
| 136 * This function takes as its arguments: | 70 * This function takes as its arguments: |
| 71 * |
| 137 * png_ptr - pointer to a png input data structure | 72 * png_ptr - pointer to a png input data structure |
| 73 * |
| 138 * io_ptr - pointer to user supplied structure containing info about | 74 * io_ptr - pointer to user supplied structure containing info about |
| 139 * the input functions. May be NULL. | 75 * the input functions. May be NULL. |
| 76 * |
| 140 * read_data_fn - pointer to a new input function that takes as its | 77 * read_data_fn - pointer to a new input function that takes as its |
| 141 * arguments a pointer to a png_struct, a pointer to | 78 * arguments a pointer to a png_struct, a pointer to |
| 142 * a location where input data can be stored, and a 32-bit | 79 * a location where input data can be stored, and a 32-bit |
| 143 * unsigned int that is the number of bytes to be read. | 80 * unsigned int that is the number of bytes to be read. |
| 144 * To exit and output any fatal error messages the new write | 81 * To exit and output any fatal error messages the new write |
| 145 * function should call png_error(png_ptr, "Error msg"). | 82 * function should call png_error(png_ptr, "Error msg"). |
| 146 * May be NULL, in which case libpng's default function will | 83 * May be NULL, in which case libpng's default function will |
| 147 * be used. | 84 * be used. |
| 148 */ | 85 */ |
| 149 void PNGAPI | 86 void PNGAPI |
| 150 png_set_read_fn(png_structp png_ptr, png_voidp io_ptr, | 87 png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr, |
| 151 png_rw_ptr read_data_fn) | 88 png_rw_ptr read_data_fn) |
| 152 { | 89 { |
| 153 if (png_ptr == NULL) | 90 if (png_ptr == NULL) |
| 154 return; | 91 return; |
| 92 |
| 155 png_ptr->io_ptr = io_ptr; | 93 png_ptr->io_ptr = io_ptr; |
| 156 | 94 |
| 157 #ifdef PNG_STDIO_SUPPORTED | 95 #ifdef PNG_STDIO_SUPPORTED |
| 158 if (read_data_fn != NULL) | 96 if (read_data_fn != NULL) |
| 159 png_ptr->read_data_fn = read_data_fn; | 97 png_ptr->read_data_fn = read_data_fn; |
| 98 |
| 160 else | 99 else |
| 161 png_ptr->read_data_fn = png_default_read_data; | 100 png_ptr->read_data_fn = png_default_read_data; |
| 162 #else | 101 #else |
| 163 png_ptr->read_data_fn = read_data_fn; | 102 png_ptr->read_data_fn = read_data_fn; |
| 164 #endif | 103 #endif |
| 165 | 104 |
| 105 #ifdef PNG_WRITE_SUPPORTED |
| 166 /* It is an error to write to a read device */ | 106 /* It is an error to write to a read device */ |
| 167 if (png_ptr->write_data_fn != NULL) | 107 if (png_ptr->write_data_fn != NULL) |
| 168 { | 108 { |
| 169 png_ptr->write_data_fn = NULL; | 109 png_ptr->write_data_fn = NULL; |
| 170 png_warning(png_ptr, | 110 png_warning(png_ptr, |
| 171 "It's an error to set both read_data_fn and write_data_fn in the "); | 111 "Can't set both read_data_fn and write_data_fn in the" |
| 172 png_warning(png_ptr, | 112 " same structure"); |
| 173 "same structure. Resetting write_data_fn to NULL."); | |
| 174 } | 113 } |
| 114 #endif |
| 175 | 115 |
| 176 #ifdef PNG_WRITE_FLUSH_SUPPORTED | 116 #ifdef PNG_WRITE_FLUSH_SUPPORTED |
| 177 png_ptr->output_flush_fn = NULL; | 117 png_ptr->output_flush_fn = NULL; |
| 178 #endif | 118 #endif |
| 179 } | 119 } |
| 180 #endif /* PNG_READ_SUPPORTED */ | 120 #endif /* READ */ |
| OLD | NEW |