Merge pull request #76 from czarkoff/loader

Loading image data from standard input

8 files changed, 192 insertions, 72 deletions

diff --git a/README.md b/README.md
index 73e3082..f48598b 100644
--- a/README.md
+++ b/README.md
@@ -20,13 +20,16 @@ Usage
     imv image1.png another_image.jpeg yet_another.TIFF
 
 ### Opening images via stdin
-    find . "*.png" | imv -
+    find . "*.png" | imv
 
 ### Open an image fullscreen
     imv -f image.jpeg
 
 ### Viewing images in a random order
-    find . "*.png" | shuf | imv -
+    find . "*.png" | shuf | imv
+
+### Viewing images from stdin
+    curl http://somesi.te/img.png | imv -
 
 ### Image picker
 imv can be used to select images in a pipeline by using the `p` hotkey to print
@@ -35,13 +38,13 @@ to list the remaining paths on exit for a "open set of images, close unwanted
 ones with `x`, then quit imv to pass the remaining images through" workflow.
 
 #### Picking a wallpaper
-    custom-set-wallpaper-script "$(find ./wallpaper -type f -name '*.jpg' | imv - | tail -n1)"
+    custom-set-wallpaper-script "$(find ./wallpaper -type f -name '*.jpg' | imv | tail -n1)"
 
 #### Deleting unwanted images
-    find -type f -name '*.jpg' | imv - | xargs rm -v
+    find -type f -name '*.jpg' | imv | xargs rm -v
 
 #### Choosing pictures to email
-    find ./holiday_pics -type f -name '*.jpg' | imv - | xargs cp -t ~/outbox
+    find ./holiday_pics -type f -name '*.jpg' | imv | xargs cp -t ~/outbox
 
 ### Slideshow
 
diff --git a/doc/imv.1 b/doc/imv.1
index cbd5c68..d883611 100644
--- a/doc/imv.1
+++ b/doc/imv.1
@@ -21,12 +21,8 @@ It supports a wide variety of image file formats, including animated gif files.
 .Nm
 reloads the current image if it detects changes to the file.
 .Pp
-When run with argument
-.Sq - ,
 .Nm
-reads the list of images from standard input.
-.Pp
-The options are as follows:
+accepts following flags:
 .Bl -tag -width Ds
 .It Fl a
 Default to showing images at actual size.
@@ -66,6 +62,17 @@ Setting this to zero disables slideshow mode, which is the default.
 .It Fl u
 Use nearest neighbour resampling. Recommended for pixel art.
 .El
+.Ss Reading from standard input
+When run with argument
+.Sq - ,
+.Nm
+reads image from standard input.
+Argument
+.Sq -
+may occur among other arguments, but only once.
+.Pp
+If no arguments supplied, reads list of files from standard input.
+.Pp
 .Sh CONTROLS
 .Bl -tag -width Ds
 .It Aq Cm left mouse button
@@ -111,6 +118,13 @@ Increase slideshow delay by one second
 .It Cm T
 Decrease slideshow delay by one second.
 When delay is zero, slideshow mode is disabled.
+.Sh EXAMPLES
+Load all files from directory
+.Pa dir :
+.Pp
+.Dl $ ls dir | imv
+or
+.Dl $ ls dir | xargs imv
 .Sh LEGAL
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
diff --git a/src/loader.c b/src/loader.c
index 883e857..1250289 100644
--- a/src/loader.c
+++ b/src/loader.c
@@ -17,10 +17,17 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 #include "loader.h"
 #include "texture.h"
+#include <limits.h>
 #include <stdlib.h>
 #include <pthread.h>
 #include <signal.h>
 
+static void block_usr1_signal(void);
+static int is_thread_cancelled(void);
+static void *bg_new_img(void *data);
+static void *bg_next_frame(void *data);
+static void error_occurred(struct imv_loader *ldr);
+
 static void block_usr1_signal(void)
 {
   sigset_t sigmask;
@@ -61,10 +68,8 @@ void imv_destroy_loader(struct imv_loader *ldr)
   }
 }
 
-static void *imv_loader_bg_new_img(void *data);
-static void *imv_loader_bg_next_frame(void *data);
-
-void imv_loader_load_path(struct imv_loader *ldr, const char *path)
+void imv_loader_load(struct imv_loader *ldr, const char *path,
+                     const void *buffer, const size_t buffer_size)
 {
   /* cancel existing thread if already running */
   if(ldr->bg_thread) {
@@ -77,7 +82,13 @@ void imv_loader_load_path(struct imv_loader *ldr, const char *path)
     free(ldr->path);
   }
   ldr->path = strdup(path);
-  pthread_create(&ldr->bg_thread, NULL, &imv_loader_bg_new_img, ldr);
+  if (strncmp(path, "-", 2) == 0) {
+    ldr->buffer = (BYTE *)buffer;
+    ldr->buffer_size = buffer_size;
+  } else if (ldr->fi_buffer != NULL) {
+    FreeImage_CloseMemory(ldr->fi_buffer);
+  }
+  pthread_create(&ldr->bg_thread, NULL, &bg_new_img, ldr);
   pthread_mutex_unlock(&ldr->lock);
 }
 
@@ -120,7 +131,7 @@ void imv_loader_load_next_frame(struct imv_loader *ldr)
   }
 
   /* kick off a new thread */
-  pthread_create(&ldr->bg_thread, NULL, &imv_loader_bg_next_frame, ldr);
+  pthread_create(&ldr->bg_thread, NULL, &bg_next_frame, ldr);
 }
 
 void imv_loader_time_passed(struct imv_loader *ldr, double dt)
@@ -140,33 +151,38 @@ void imv_loader_time_passed(struct imv_loader *ldr, double dt)
   }
 }
 
-static void imv_loader_error_occurred(struct imv_loader *ldr)
-{
-  pthread_mutex_lock(&ldr->lock);
-  if(ldr->out_err) {
-    free(ldr->out_err);
-  }
-  ldr->out_err = strdup(ldr->path);
-  pthread_mutex_unlock(&ldr->lock);
-}
-
-static void *imv_loader_bg_new_img(void *data)
+static void *bg_new_img(void *data)
 {
   /* so we can poll for it */
   block_usr1_signal();
 
   struct imv_loader *ldr = data;
+  char path[PATH_MAX] = "-";
 
   pthread_mutex_lock(&ldr->lock);
-  char *path = strdup(ldr->path);
+  int from_stdin = !strncmp(path, ldr->path, 2);
+  if(!from_stdin) {
+    (void)snprintf(path, PATH_MAX, "%s", ldr->path);
+  }
   pthread_mutex_unlock(&ldr->lock);
 
-  FREE_IMAGE_FORMAT fmt = FreeImage_GetFileType(path, 0);
-
+  FREE_IMAGE_FORMAT fmt;
+  if (from_stdin) {
+    pthread_mutex_lock(&ldr->lock);
+    ldr->fi_buffer = FreeImage_OpenMemory(ldr->buffer, ldr->buffer_size);
+    fmt = FreeImage_GetFileTypeFromMemory(ldr->fi_buffer, 0);
+    pthread_mutex_unlock(&ldr->lock);
+  } else {
+    fmt = FreeImage_GetFileType(path, 0);
+  }
   if(fmt == FIF_UNKNOWN) {
-    imv_loader_error_occurred(ldr);
-    free(path);
-    return 0;
+    if (from_stdin) {
+      pthread_mutex_lock(&ldr->lock);
+      FreeImage_CloseMemory(ldr->fi_buffer);
+      pthread_mutex_unlock(&ldr->lock);
+    }
+    error_occurred(ldr);
+    return NULL;
   }
 
   int num_frames = 1;
@@ -176,15 +192,21 @@ static void *imv_loader_bg_new_img(void *data)
   int raw_frame_time = 100; /* default to 100 */
 
   if(fmt == FIF_GIF) {
-    mbmp = FreeImage_OpenMultiBitmap(FIF_GIF, path,
+    if(from_stdin) {
+      pthread_mutex_lock(&ldr->lock);
+      mbmp = FreeImage_LoadMultiBitmapFromMemory(FIF_GIF, ldr->fi_buffer,
+          GIF_LOAD256);
+      pthread_mutex_unlock(&ldr->lock);
+    } else {
+      mbmp = FreeImage_OpenMultiBitmap(FIF_GIF, path,
       /* don't create file */ 0,
       /* read only */ 1,
       /* keep in memory */ 1,
       /* flags */ GIF_LOAD256);
-    free(path);
+    }
     if(!mbmp) {
-      imv_loader_error_occurred(ldr);
-      return 0;
+      error_occurred(ldr);
+      return NULL;
     }
 
     num_frames = FreeImage_GetPageCount(mbmp);
@@ -205,17 +227,27 @@ static void *imv_loader_bg_new_img(void *data)
   } else {
     /* Future TODO: If we load image line-by-line we could stop loading large
      * ones before wasting much more time/memory on them. */
-    FIBITMAP *image = FreeImage_Load(fmt, path, 0);
-    free(path);
+    FIBITMAP *image;
+    if(from_stdin) {
+      pthread_mutex_lock(&ldr->lock);
+      image = FreeImage_LoadFromMemory(fmt, ldr->fi_buffer, 0);
+      pthread_mutex_unlock(&ldr->lock);
+    } else {
+      image = FreeImage_Load(fmt, path, 0);
+    }
     if(!image) {
-      imv_loader_error_occurred(ldr);
-      return 0;
+      error_occurred(ldr);
+      pthread_mutex_lock(&ldr->lock);
+      FreeImage_CloseMemory(ldr->fi_buffer);
+      ldr->fi_buffer = NULL;
+      pthread_mutex_unlock(&ldr->lock);
+      return NULL;
     }
 
     /* Check for cancellation before we convert pixel format */
     if(is_thread_cancelled()) {
       FreeImage_Unload(image);
-      return 0;
+      return NULL;
     }
 
     width = FreeImage_GetWidth(bmp);
@@ -236,7 +268,7 @@ static void *imv_loader_bg_new_img(void *data)
       FreeImage_Unload(bmp);
     }
     pthread_mutex_unlock(&ldr->lock);
-    return 0;
+    return NULL;
   }
 
   if(ldr->mbmp) {
@@ -262,10 +294,10 @@ static void *imv_loader_bg_new_img(void *data)
   ldr->frame_time = (double)raw_frame_time * 0.0001;
 
   pthread_mutex_unlock(&ldr->lock);
-  return 0;
+  return NULL;
 }
 
-static void *imv_loader_bg_next_frame(void *data)
+static void *bg_next_frame(void *data)
 {
   struct imv_loader *ldr = data;
 
@@ -273,7 +305,7 @@ static void *imv_loader_bg_next_frame(void *data)
   int num_frames = ldr->num_frames;
   if(num_frames < 2) {
     pthread_mutex_unlock(&ldr->lock);
-    return 0;
+    return NULL;
   }
 
   FITAG *tag = NULL;
@@ -371,5 +403,15 @@ static void *imv_loader_bg_next_frame(void *data)
   ldr->out_is_new_image = 0;
 
   pthread_mutex_unlock(&ldr->lock);
-  return 0;
+  return NULL;
+}
+
+static void error_occurred(struct imv_loader *ldr)
+{
+  pthread_mutex_lock(&ldr->lock);
+  if(ldr->out_err) {
+    free(ldr->out_err);
+  }
+  ldr->out_err = strdup(ldr->path);
+  pthread_mutex_unlock(&ldr->lock);
 }
diff --git a/src/loader.h b/src/loader.h
index 65c8689..6e20349 100644
--- a/src/loader.h
+++ b/src/loader.h
@@ -28,6 +28,9 @@ struct imv_loader {
   pthread_mutex_t lock;
   pthread_t bg_thread;
   char *path;
+  BYTE *buffer;
+  size_t buffer_size;
+  FIMEMORY *fi_buffer;
   FIBITMAP *out_bmp;
   int out_is_new_image;
   char *out_err;
@@ -48,7 +51,8 @@ void imv_init_loader(struct imv_loader *img);
 void imv_destroy_loader(struct imv_loader *img);
 
 /* Asynchronously load the given file */
-void imv_loader_load_path(struct imv_loader *ldr, const char *path);
+void imv_loader_load(struct imv_loader *ldr, const char *path,
+                     const void *buffer, const size_t buffer_size);
 
 /* Returns 1 if image data is available. 0 if not. Caller is responsible for
  * cleaning up the data returned. Each image is only returned once.
diff --git a/src/main.c b/src/main.c
index 25ffce1..7ba55ec 100644
--- a/src/main.c
+++ b/src/main.c
@@ -24,6 +24,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include <FreeImage.h>
 #include <getopt.h>
 #include <ctype.h>
+#include <errno.h>
 
 #include "loader.h"
 #include "texture.h"
@@ -33,7 +34,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 struct {
   int fullscreen;
-  int sin;
+  int stdin_list;
   int recursive;
   int actual;
   int nearest_neighbour;
@@ -49,7 +50,7 @@ struct {
   const char *font;
 } g_options = {
   .fullscreen = 0,
-  .sin = 0,
+  .stdin_list = 0,
   .recursive = 0,
   .actual = 0,
   .nearest_neighbour = 0,
@@ -72,7 +73,7 @@ static void print_usage(const char* name)
   "Usage: %s [-rfaudlh] [-n <NUM|PATH>] [-b BG] [-e FONT:SIZE] [-t SECONDS] [-] [images...]\n"
   "\n"
   "Flags:\n"
-  "   -: Read paths from stdin. One path per line.\n"
+  "   -: Read image from stdin. One path per line.\n"
   "  -r: Recursively search input paths.\n"
   "  -f: Start in fullscreen mode\n"
   "  -a: Default to images' actual size\n"
@@ -137,8 +138,8 @@ static void parse_args(int argc, char** argv)
     switch(o) {
       case 'f': g_options.fullscreen = 1;   break;
       case 'i':
-        g_options.sin = 1;
-        fprintf(stderr, "Warning: '-i' is deprecated. Just use '-' instead.\n");
+        g_options.stdin_list = 1;
+        fprintf(stderr, "Warning: '-i' is deprecated. No flag is needed.\n");
         break;
       case 'r': g_options.recursive = 1;           break;
       case 'a': g_options.actual = 1;              break;
@@ -193,31 +194,23 @@ static void parse_args(int argc, char** argv)
 
 int main(int argc, char** argv)
 {
-  if(argc < 2) {
-    print_usage(argv[0]);
-    exit(1);
-  }
-
   struct imv_navigator nav;
   imv_navigator_init(&nav);
 
   /* parse any command line options given */
   parse_args(argc, argv);
 
-  /* handle any image paths given as arguments */
-  for(int i = optind; i < argc; ++i) {
-    /* special case: '-' is actually an option */
-    if(!strcmp("-",argv[i])) {
-      g_options.sin = 1;
-      continue;
-    }
-    /* add the given path to the list to load */
-    imv_navigator_add(&nav, argv[i], g_options.recursive);
+  argc -= optind;
+  argv += optind;
+
+  /* if no names are given, expect them on stdin */
+  if(argc == 0) {
+    g_options.stdin_list = 1;
   }
 
   /* if the user asked us to load paths from stdin, now is the time */
-  if(g_options.sin) {
-    char buf[512];
+  if(g_options.stdin_list) {
+    char buf[PATH_MAX];
     while(fgets(buf, sizeof(buf), stdin)) {
       size_t len = strlen(buf);
       if(buf[len-1] == '\n') {
@@ -229,6 +222,30 @@ int main(int argc, char** argv)
     }
   }
 
+  void *stdin_buffer = NULL;
+  size_t stdin_buffer_size = 0;
+  int stdin_error = 0;
+
+  /* handle any image paths given as arguments */
+  for(int i = 0; i < argc; ++i) {
+    /* special case: '-' is actually an option */
+    if(!strcmp("-",argv[i])) {
+      if (stdin_buffer) {
+        fprintf(stderr, "Can't read from stdin twice\n");
+        exit(1);
+      }
+      stdin_buffer_size = read_from_stdin(&stdin_buffer);
+      if (stdin_buffer_size == 0) {
+        perror(NULL);
+        continue; /* we can't recover from the freed buffer, just ignore it */
+      }
+      stdin_error = errno;
+      errno = 0; /* clear errno */
+    }
+    /* add the given path to the list to load */
+    imv_navigator_add(&nav, argv[i], g_options.recursive);
+  }
+
   /* if we weren't given any paths we have nothing to view. exit */
   if(!imv_navigator_selection(&nav)) {
     fprintf(stderr, "No input files. Exiting.\n");
@@ -435,6 +452,15 @@ int main(int argc, char** argv)
     char *err_path = imv_loader_get_error(&ldr);
     if(err_path) {
       imv_navigator_remove(&nav, err_path);
+      if (strncmp(err_path, "-", 2) == 0) {
+        free(stdin_buffer);
+        stdin_buffer_size = 0;
+        if (stdin_error != 0) {
+          errno = stdin_error;
+          perror("Failed to load image from standard input");
+          errno = 0;
+        }
+      }
       free(err_path);
     }
 
@@ -451,7 +477,7 @@ int main(int argc, char** argv)
           nav.cur_path + 1, nav.num_paths, current_path);
       imv_viewport_set_title(&view, title);
 
-      imv_loader_load_path(&ldr, current_path);
+      imv_loader_load(&ldr, current_path, stdin_buffer, stdin_buffer_size);
       view.playing = 1;
     }
 
diff --git a/src/navigator.c b/src/navigator.c
index fb2a3cd..dd5124d 100644
--- a/src/navigator.c
+++ b/src/navigator.c
@@ -17,6 +17,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 #include "navigator.h"
 
+#include <limits.h>
 #include <sys/stat.h>
 #include <dirent.h>
 #include <stdlib.h>
@@ -84,7 +85,7 @@ static void add_item(struct imv_navigator *nav, const char *path,
 void imv_navigator_add(struct imv_navigator *nav, const char *path,
                        int recursive)
 {
-  char path_buf[512];
+  char path_buf[PATH_MAX];
   struct stat path_info;
   stat(path, &path_info);
   if(S_ISDIR(path_info.st_mode)) {
diff --git a/src/util.c b/src/util.c
index dac23d4..0a15238 100644
--- a/src/util.c
+++ b/src/util.c
@@ -16,9 +16,36 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
 
 #include "util.h"
-
+#include <unistd.h>
+#include <stddef.h>
+#include <errno.h>
 #include <fontconfig/fontconfig.h>
 
+size_t read_from_stdin(void **buffer) {
+  size_t len = 0;
+  ssize_t r;
+  size_t step = 1024; /* Arbitrary value of 1 KiB */
+  void *p;
+
+  errno = 0; /* clear errno */
+
+  for(*buffer = NULL; (*buffer = realloc((p = *buffer), len + step));
+      len += (size_t)r) {
+    if((r = read(STDIN_FILENO, (uint8_t *)*buffer + len, step)) <= 0) {
+      break;
+    }
+  }
+
+  /* realloc(3) leaves old buffer allocated in case of error */
+  if(*buffer == NULL && p != NULL) {
+    int save = errno;
+    free(p);
+    errno = save;
+    len = 0;
+  }
+  return len;
+}
+
 TTF_Font *load_font(const char *font_spec)
 {
   int font_size;
diff --git a/src/util.h b/src/util.h
index 3625a6c..09d5554 100644
--- a/src/util.h
+++ b/src/util.h
@@ -21,6 +21,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include <SDL2/SDL.h>
 #include <SDL2/SDL_ttf.h>
 
+/* Read binary data from stdin into buffer */
+size_t read_from_stdin(void **buffer);
+
 /* Creates a new SDL_Texture* containing a chequeboard texture */
 SDL_Texture *create_chequered(SDL_Renderer *renderer);