| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* pngwio.c - functions for data output |
| * |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file and, per its terms, should not be removed: |
| * |
| * Last changed in libpng 1.6.15 [November 20, 2014] |
| * Copyright (c) 1998-2014 Glenn Randers-Pehrson |
| * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| * (Version 0.88 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 output. Users who need |
| * special handling are expected to write functions that have the same |
| * arguments as these and perform similar functions, but that possibly |
| * use different output methods. Note that you shouldn't change these |
| * functions, but rather write replacement functions and then change |
| * them at run time with png_set_write_fn(...). |
| */ |
| |
| #include "pngpriv.h" |
| |
| #ifdef PNG_WRITE_SUPPORTED |
| |
| /* Write the data to whatever output you are using. The default routine |
| * writes to 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 writes. This should never be asked |
| * to write more than 64K on a 16-bit machine. |
| */ |
| |
| void /* PRIVATE */ |
| png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length) |
| { |
| /* NOTE: write_data_fn must not change the buffer! */ |
| if (png_ptr->write_data_fn != NULL ) |
| (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data), |
| length); |
| |
| else |
| png_error(png_ptr, "Call to NULL write function"); |
| } |
| |
| #ifdef PNG_STDIO_SUPPORTED |
| /* This is the function that does the actual writing of data. If you are |
| * not writing to a standard C stream, you should create a replacement |
| * write_data function and use it at run time with png_set_write_fn(), rather |
| * than changing the library. |
| */ |
| void PNGCBAPI |
| png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) |
| { |
| png_size_t check; |
| |
| if (png_ptr == NULL) |
| return; |
| |
| check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); |
| |
| if (check != length) |
| png_error(png_ptr, "Write Error"); |
| } |
| #endif |
| |
| /* This function is called to output any data pending writing (normally |
| * to disk). After png_flush is called, there should be no data pending |
| * writing in any buffers. |
| */ |
| #ifdef PNG_WRITE_FLUSH_SUPPORTED |
| void /* PRIVATE */ |
| png_flush(png_structrp png_ptr) |
| { |
| if (png_ptr->output_flush_fn != NULL) |
| (*(png_ptr->output_flush_fn))(png_ptr); |
| } |
| |
| # ifdef PNG_STDIO_SUPPORTED |
| void PNGCBAPI |
| png_default_flush(png_structp png_ptr) |
| { |
| png_FILE_p io_ptr; |
| |
| if (png_ptr == NULL) |
| return; |
| |
| io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr)); |
| fflush(io_ptr); |
| } |
| # endif |
| #endif |
| |
| /* This function allows the application to supply new output functions for |
| * libpng if standard C streams aren't being used. |
| * |
| * This function takes as its arguments: |
| * png_ptr - pointer to a png output data structure |
| * io_ptr - pointer to user supplied structure containing info about |
| * the output functions. May be NULL. |
| * write_data_fn - pointer to a new output function that takes as its |
| * arguments a pointer to a png_struct, a pointer to |
| * data to be written, and a 32-bit unsigned int that is |
| * the number of bytes to be written. The new write |
| * function should call png_error(png_ptr, "Error msg") |
| * to exit and output any fatal error messages. May be |
| * NULL, in which case libpng's default function will |
| * be used. |
| * flush_data_fn - pointer to a new flush function that takes as its |
| * arguments a pointer to a png_struct. After a call to |
| * the flush function, there should be no data in any buffers |
| * or pending transmission. If the output method doesn't do |
| * any buffering of output, a function prototype must still be |
| * supplied although it doesn't have to do anything. If |
| * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile |
| * time, output_flush_fn will be ignored, although it must be |
| * supplied for compatibility. May be NULL, in which case |
| * libpng's default function will be used, if |
| * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not |
| * a good idea if io_ptr does not point to a standard |
| * *FILE structure. |
| */ |
| void PNGAPI |
| png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr, |
| png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) |
| { |
| if (png_ptr == NULL) |
| return; |
| |
| png_ptr->io_ptr = io_ptr; |
| |
| #ifdef PNG_STDIO_SUPPORTED |
| if (write_data_fn != NULL) |
| png_ptr->write_data_fn = write_data_fn; |
| |
| else |
| png_ptr->write_data_fn = png_default_write_data; |
| #else |
| png_ptr->write_data_fn = write_data_fn; |
| #endif |
| |
| #ifdef PNG_WRITE_FLUSH_SUPPORTED |
| # ifdef PNG_STDIO_SUPPORTED |
| |
| if (output_flush_fn != NULL) |
| png_ptr->output_flush_fn = output_flush_fn; |
| |
| else |
| png_ptr->output_flush_fn = png_default_flush; |
| |
| # else |
| png_ptr->output_flush_fn = output_flush_fn; |
| # endif |
| #else |
| PNG_UNUSED(output_flush_fn) |
| #endif /* WRITE_FLUSH */ |
| |
| #ifdef PNG_READ_SUPPORTED |
| /* It is an error to read while writing a png file */ |
| if (png_ptr->read_data_fn != NULL) |
| { |
| png_ptr->read_data_fn = NULL; |
| |
| png_warning(png_ptr, |
| "Can't set both read_data_fn and write_data_fn in the" |
| " same structure"); |
| } |
| #endif |
| } |
| #endif /* WRITE */ |
