From 6c54e8119e8ff17c3e652cf500a481b5ec4dff78 Mon Sep 17 00:00:00 2001
From: twinaphex <libretro@gmail.com>
Date: Sat, 21 Feb 2015 03:57:34 +0100
Subject: [PATCH] (NBIO) Make all nbio functions nonblocking

---
 .../formats/png/rpng_decode_fnbio.c           | 55 ++++++++++++-------
 libretro-common/formats/png/rpng_test.c       | 16 ++++--
 libretro-common/include/formats/rpng.h        |  2 +
 3 files changed, 49 insertions(+), 24 deletions(-)

diff --git a/libretro-common/formats/png/rpng_decode_fnbio.c b/libretro-common/formats/png/rpng_decode_fnbio.c
index 6161b457a5..a9292f6ce5 100644
--- a/libretro-common/formats/png/rpng_decode_fnbio.c
+++ b/libretro-common/formats/png/rpng_decode_fnbio.c
@@ -331,10 +331,7 @@ void rpng_nbio_load_image_free(struct rpng_t *rpng)
 
 struct rpng_t *rpng_nbio_load_image_argb_init(const char *path)
 {
-   unsigned i;
-   char header[8];
    size_t file_len;
-   bool looped = false;
    struct nbio_t* nbread = NULL;
    struct rpng_t *rpng = (struct rpng_t*)calloc(1, sizeof(struct rpng_t));
 
@@ -352,22 +349,6 @@ struct rpng_t *rpng_nbio_load_image_argb_init(const char *path)
 
    nbio_begin_read(nbread);
 
-   while (!nbio_iterate(nbread))
-      looped = true;
-
-   rpng->ptr = nbio_get_ptr(nbread, &file_len);
-   (void)looped;
-
-   rpng->buff_data = (uint8_t*)rpng->ptr;
-
-   for (i = 0; i < 8; i++)
-      header[i] = rpng->buff_data[i];
-
-   if (memcmp(header, png_magic, sizeof(png_magic)) != 0)
-      goto error;
-
-   rpng->buff_data += 8;
-
    return rpng;
 
 error:
@@ -377,3 +358,39 @@ error:
       free(rpng);
    return NULL;
 }
+
+bool rpng_nbio_load_image_argb_start(struct rpng_t *rpng)
+{
+   unsigned i;
+   size_t file_len;
+   char header[8];
+   struct nbio_t *nbread = NULL;
+
+   if (!rpng)
+      return false;
+   
+   nbread    = (struct nbio_t*)rpng->userdata;
+
+   if (!nbread)
+      return false;
+
+   rpng->ptr = nbio_get_ptr(nbread, &file_len);
+
+   if (!rpng->ptr)
+      return false;
+
+   rpng->buff_data = (uint8_t*)rpng->ptr;
+
+   if (!rpng->buff_data)
+      return false;
+
+   for (i = 0; i < 8; i++)
+      header[i] = rpng->buff_data[i];
+
+   if (memcmp(header, png_magic, sizeof(png_magic)) != 0)
+      return false;
+
+   rpng->buff_data += 8;
+
+   return true;
+}
diff --git a/libretro-common/formats/png/rpng_test.c b/libretro-common/formats/png/rpng_test.c
index add6c4b343..68b1b6beaf 100644
--- a/libretro-common/formats/png/rpng_test.c
+++ b/libretro-common/formats/png/rpng_test.c
@@ -21,6 +21,7 @@
  */
 
 #include <formats/rpng.h>
+#include <file/nbio.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
@@ -42,12 +43,17 @@ static bool rpng_nbio_load_image_argb(const char *path, uint32_t **data,
       goto end;
    }
 
-   while (1)
-   {
-      if (!rpng_nbio_load_image_argb_iterate(
-            rpng->buff_data, rpng))
-         break;
+   while (!nbio_iterate((struct nbio_t*)rpng->userdata));
 
+   if (!rpng_nbio_load_image_argb_start(rpng))
+   {
+      ret = false;
+      goto end;
+   }
+
+   while (rpng_nbio_load_image_argb_iterate(
+            rpng->buff_data, rpng))
+   {
       rpng->buff_data += 4 + 4 + rpng->chunk.size + 4;
    }
 
diff --git a/libretro-common/include/formats/rpng.h b/libretro-common/include/formats/rpng.h
index e5d77561f6..757b3bafb3 100644
--- a/libretro-common/include/formats/rpng.h
+++ b/libretro-common/include/formats/rpng.h
@@ -90,6 +90,8 @@ bool rpng_nbio_load_image_argb_iterate(uint8_t *buf,
 bool rpng_nbio_load_image_argb_process(struct rpng_t *rpng,
       uint32_t **data, unsigned *width, unsigned *height);
 
+bool rpng_nbio_load_image_argb_start(struct rpng_t *rpng);
+
 #ifdef HAVE_ZLIB_DEFLATE
 bool rpng_save_image_argb(const char *path, const uint32_t *data,
       unsigned width, unsigned height, unsigned pitch);