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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
commit0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch)
treea31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /media/libpng/pngrio.c
parentInitial commit. (diff)
downloadfirefox-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.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/media/libpng/pngrio.c b/media/libpng/pngrio.c
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+
+/* 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 */