Commit FS#11799 by Alexander Meshcheryakov. Improves the text viewer plugin to write to the disk less often, and correct several minor bugs.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28833 a1c6a512-1295-4272-9138-f99709370657

9 files changed, 131 insertions, 64 deletions

diff --git a/apps/plugins/text_viewer/tv_action.c b/apps/plugins/text_viewer/tv_action.c
index 54cec38..3a0d895 100644
--- a/apps/plugins/text_viewer/tv_action.c
+++ b/apps/plugins/text_viewer/tv_action.c
@@ -28,6 +28,9 @@
 #include "tv_settings.h"
 #include "tv_window.h"
 
+bool bookmarks_changed = false;
+bool scrolled = false;
+
 bool tv_init_action(unsigned char **buf, size_t *size)
 {
     /* initialize bookmarks and window modules */
@@ -36,10 +39,6 @@ bool tv_init_action(unsigned char **buf, size_t *size)
 
 static void tv_finalize_action(void)
 {
-    /* save preference and bookmarks */
-    if (!tv_save_settings())
-        rb->splash(HZ, "Can't save preferences and bookmarks");
-
     /* finalize bookmark modules */
     tv_finalize_bookmark();
 
@@ -50,8 +49,19 @@ static void tv_finalize_action(void)
 void tv_exit(void)
 {
     /* save preference and bookmarks */
-    if (!tv_save_settings())
-        rb->splash(HZ, "Can't save preferences and bookmarks");
+    DEBUGF("preferences_changed=%d\tbookmarks_changed=%d\tscrolled=%d\n",preferences_changed,bookmarks_changed,scrolled);
+    if  ( preferences_changed || bookmarks_changed
+#ifndef HAVE_DISK_STORAGE
+         || scrolled
+#endif
+        )
+    {
+        DEBUGF("Saving settings\n");
+        if (!tv_save_settings())
+            rb->splash(HZ, "Can't save preferences and bookmarks");
+    }
+    else
+        DEBUGF("Skip saving settings\n");
 
     /* finalize modules */
     tv_finalize_action();
@@ -95,6 +105,7 @@ void tv_scroll_up(unsigned mode)
 #endif
     }
     tv_move_screen(offset_page, offset_line, SEEK_CUR);
+    scrolled = true;
 }
 
 void tv_scroll_down(unsigned mode)
@@ -111,6 +122,7 @@ void tv_scroll_down(unsigned mode)
 #endif
     }
     tv_move_screen(offset_page, offset_line, SEEK_CUR);
+    scrolled = true;
 }
 
 void tv_scroll_left(unsigned mode)
@@ -130,6 +142,7 @@ void tv_scroll_left(unsigned mode)
         offset_window--;
     }
     tv_move_window(offset_window, offset_column);
+    scrolled = true;
 }
 
 void tv_scroll_right(unsigned mode)
@@ -149,6 +162,7 @@ void tv_scroll_right(unsigned mode)
         offset_window++;
     }
     tv_move_window(offset_window, offset_column);
+    scrolled = true;
 }
 
 void tv_top(void)
@@ -186,4 +200,5 @@ unsigned tv_menu(void)
 void tv_add_or_remove_bookmark(void)
 {
     tv_toggle_bookmark();
+    bookmarks_changed = true;
 }
diff --git a/apps/plugins/text_viewer/tv_bookmark.c b/apps/plugins/text_viewer/tv_bookmark.c
index 815e7a1..5f77d2a 100644
--- a/apps/plugins/text_viewer/tv_bookmark.c
+++ b/apps/plugins/text_viewer/tv_bookmark.c
@@ -32,7 +32,6 @@ enum {
     TV_BOOKMARK_USER   = 2,
 };
 
-#define SERIALIZE_BOOKMARK_SIZE 8
 
 struct tv_bookmark_info {
     struct tv_screen_pos pos;
@@ -287,11 +286,8 @@ bool tv_deserialize_bookmarks(int fd)
     return res;
 }
 
-static bool tv_write_bookmark_info(int fd, const struct tv_bookmark_info *b)
+static void tv_write_bookmark_info(unsigned char *p, const struct tv_bookmark_info *b)
 {
-    unsigned char buf[SERIALIZE_BOOKMARK_SIZE];
-    unsigned char *p = buf;
-
     *p++ = b->pos.file_pos >> 24;
     *p++ = b->pos.file_pos >> 16;
     *p++ = b->pos.file_pos >> 8;
@@ -302,21 +298,17 @@ static bool tv_write_bookmark_info(int fd, const struct tv_bookmark_info *b)
 
     *p++ = b->pos.line;
     *p   = b->flag;
-
-    return (rb->write(fd, buf, SERIALIZE_BOOKMARK_SIZE) >= 0);
 }
 
-int tv_serialize_bookmarks(int fd)
+int tv_serialize_bookmarks(unsigned char *buf)
 {
     int i;
 
-    if (rb->write(fd, &bookmark_count, 1) < 0)
-        return 0;
+    buf[0] = bookmark_count;
 
     for (i = 0; i < bookmark_count; i++)
     {
-        if (!tv_write_bookmark_info(fd, &bookmarks[i]))
-            break;
+        tv_write_bookmark_info(buf + i * SERIALIZE_BOOKMARK_SIZE + 1, &bookmarks[i]);
     }
     return i * SERIALIZE_BOOKMARK_SIZE + 1;
 }
diff --git a/apps/plugins/text_viewer/tv_bookmark.h b/apps/plugins/text_viewer/tv_bookmark.h
index b0b9107..85b52b2 100644
--- a/apps/plugins/text_viewer/tv_bookmark.h
+++ b/apps/plugins/text_viewer/tv_bookmark.h
@@ -29,6 +29,7 @@
 
 /* Maximum amount of register possible bookmarks */
 #define TV_MAX_BOOKMARKS 16
+#define SERIALIZE_BOOKMARK_SIZE 8
 
 /*
  * initialize the bookmark module
@@ -83,7 +84,7 @@ void tv_create_system_bookmark(void);
  * Return
  *     the size of the result
  */
-int tv_serialize_bookmarks(int fd);
+int tv_serialize_bookmarks(unsigned char *buf);
 
 /*
  * deserialize the bookmark array
diff --git a/apps/plugins/text_viewer/tv_menu.c b/apps/plugins/text_viewer/tv_menu.c
index 5e79fd4..9be8312 100644
--- a/apps/plugins/text_viewer/tv_menu.c
+++ b/apps/plugins/text_viewer/tv_menu.c
@@ -329,6 +329,8 @@ unsigned tv_display_menu(void)
         case 1: /* change settings */
             tv_copy_preferences(&new_prefs);
             result = tv_options_menu();
+            if (tv_compare_preferences(&new_prefs))
+                preferences_changed = true;
             if (!tv_set_preferences(&new_prefs))
                 result = TV_MENU_RESULT_ERROR;
             break;
diff --git a/apps/plugins/text_viewer/tv_preferences.c b/apps/plugins/text_viewer/tv_preferences.c
index 5e6677e..6d5c112 100644
--- a/apps/plugins/text_viewer/tv_preferences.c
+++ b/apps/plugins/text_viewer/tv_preferences.c
@@ -28,6 +28,8 @@ static struct tv_preferences prefs;
 /* read-only preferences pointer, for access by other files */
 const struct tv_preferences * const preferences = &prefs;
 
+bool preferences_changed = false;
+
 static int listner_count = 0;
 
 #define TV_MAX_LISTNERS 5
@@ -91,6 +93,11 @@ void tv_copy_preferences(struct tv_preferences *copy_prefs)
     rb->memcpy(copy_prefs, preferences, sizeof(struct tv_preferences));
 }
 
+bool tv_compare_preferences(struct tv_preferences *copy_prefs)
+{
+    return rb->memcmp(copy_prefs, preferences, sizeof(struct tv_preferences)) != 0;
+}
+
 void tv_set_default_preferences(struct tv_preferences *p)
 {
     p->word_mode = WM_WRAP;
diff --git a/apps/plugins/text_viewer/tv_preferences.h b/apps/plugins/text_viewer/tv_preferences.h
index bc871a7..bb448b0 100644
--- a/apps/plugins/text_viewer/tv_preferences.h
+++ b/apps/plugins/text_viewer/tv_preferences.h
@@ -104,6 +104,7 @@ struct tv_preferences {
  *     global pointer to the preferences (read-only)
  */
 extern const struct tv_preferences * const preferences;
+extern bool preferences_changed;
 
 /*
  * change the preferences
@@ -126,6 +127,15 @@ bool tv_set_preferences(const struct tv_preferences *new_prefs);
 void tv_copy_preferences(struct tv_preferences *copy_prefs);
 
 /*
+ * compare the preferences structs (binary)
+ *
+ * return
+ *     true  differs
+ *     false identical
+ */
+bool tv_compare_preferences(struct tv_preferences *copy_prefs);
+
+/*
  * set the default settings
  *
  * [Out] p
diff --git a/apps/plugins/text_viewer/tv_settings.c b/apps/plugins/text_viewer/tv_settings.c
index 3004ac3..20e8212 100644
--- a/apps/plugins/text_viewer/tv_settings.c
+++ b/apps/plugins/text_viewer/tv_settings.c
@@ -120,6 +120,10 @@
 #define TV_SETTINGS_FIRST_VERSION 0x32
 
 #define TV_PREFERENCES_SIZE       (28 + MAX_PATH)
+#define TV_MAX_FILE_RECORD_SIZE   (MAX_PATH+2 + TV_PREFERENCES_SIZE + TV_MAX_BOOKMARKS*SERIALIZE_BOOKMARK_SIZE+1)
+
+static off_t stored_preferences_offset = 0;
+static int stored_preferences_size = 0;
 
 /* ----------------------------------------------------------------------------
  * read/write the preferences
@@ -220,9 +224,8 @@ static bool tv_read_preferences(int pfd, int version, struct tv_preferences *pre
     return true;
 }
 
-static bool tv_write_preferences(int pfd, const struct tv_preferences *prefs)
+static void tv_serialize_preferences(unsigned char *buf, const struct tv_preferences *prefs)
 {
-    unsigned char buf[TV_PREFERENCES_SIZE];
     unsigned char *p = buf;
 
     rb->memset(buf, 0, TV_PREFERENCES_SIZE);
@@ -248,6 +251,13 @@ static bool tv_write_preferences(int pfd, const struct tv_preferences *prefs)
 #ifdef HAVE_LCD_BITMAP
     rb->strlcpy(buf + 28, prefs->font_name, MAX_PATH);
 #endif
+}
+
+static bool tv_write_preferences(int pfd, const struct tv_preferences *prefs)
+{
+    unsigned char buf[TV_PREFERENCES_SIZE];
+    
+    tv_serialize_preferences(buf, prefs);
 
     return (rb->write(pfd, buf, TV_PREFERENCES_SIZE) >= 0);
 }
@@ -427,6 +437,7 @@ bool tv_load_settings(const unsigned char *file_name)
     int version;
     unsigned int size;
     struct tv_preferences prefs;
+    off_t current_pref_offset;
 
     if (!rb->file_exists(TV_SETTINGS_FILE))
         tv_convert_settings_file();
@@ -438,6 +449,8 @@ bool tv_load_settings(const unsigned char *file_name)
         {
             version = buf[TV_SETTINGS_HEADER_SIZE - 1] - TV_SETTINGS_FIRST_VERSION;
             fcount = (buf[TV_SETTINGS_HEADER_SIZE] << 8) | buf[TV_SETTINGS_HEADER_SIZE+1];
+            
+            current_pref_offset = rb->lseek(fd, 0, SEEK_CUR);
 
             for (i = 0; i < fcount; i++)
             {
@@ -448,10 +461,15 @@ bool tv_load_settings(const unsigned char *file_name)
                     {
                         if (tv_read_preferences(fd, version, &prefs))
                             res = tv_deserialize_bookmarks(fd);
+                        
+                        if (res) {
+                            stored_preferences_offset = current_pref_offset;
+                            stored_preferences_size = size;
+                        }
 
                         break;
                     }
-                    rb->lseek(fd, size, SEEK_CUR);
+                    current_pref_offset = rb->lseek(fd, size, SEEK_CUR);
                 }
             }
             rb->close(fd);
@@ -473,38 +491,74 @@ bool tv_load_settings(const unsigned char *file_name)
     return tv_set_preferences(&prefs);
 }
 
-static bool tv_copy_settings(int sfd, int dfd, int size)
-{
-    unsigned char buf[MAX_PATH];
-    int i = size / MAX_PATH;
-
-    size %= MAX_PATH;
-
-    while (i--)
-    {
-        if ((rb->read(sfd, buf, MAX_PATH) < 0) || (rb->write(dfd, buf, MAX_PATH) < 0))
-            return false;
-    }
-
-    return ((rb->read(sfd, buf, size) >= 0) && (rb->write(dfd, buf, size) >= 0));
-}
-
 bool tv_save_settings(void)
 {
-    unsigned char buf[MAX_PATH+2];
+    unsigned char buf[TV_MAX_FILE_RECORD_SIZE];
+    unsigned char preferences_buf[TV_MAX_FILE_RECORD_SIZE];
     unsigned int fcount = 0;
+    unsigned int new_fcount = 0;
     unsigned int i;
     int ofd = -1;
     int tfd;
     off_t size;
+    off_t preferences_buf_size;
     bool res = true;
 
     /* add reading page to bookmarks */
     tv_create_system_bookmark();
 
+    /* storing preferences record in memory */
+    rb->memset(preferences_buf, 0, MAX_PATH);
+    rb->strlcpy(preferences_buf, preferences->file_name, MAX_PATH);
+    preferences_buf_size = MAX_PATH + 2;
+
+    tv_serialize_preferences(preferences_buf + preferences_buf_size, preferences);
+    preferences_buf_size += TV_PREFERENCES_SIZE;
+    preferences_buf_size += tv_serialize_bookmarks(preferences_buf + preferences_buf_size);
+    size = preferences_buf_size - (MAX_PATH + 2);
+    preferences_buf[MAX_PATH + 0] = size >> 8;
+    preferences_buf[MAX_PATH + 1] = size;
+
+    
+    /* Just overwrite preferences if possible*/
+    if ( (stored_preferences_offset > 0) && (stored_preferences_size == size) )
+    {
+        DEBUGF("Saving preferences: overwriting\n");
+        if ((tfd = rb->open(TV_SETTINGS_FILE, O_WRONLY)) < 0)
+            return false;
+        rb->lseek(tfd, stored_preferences_offset, SEEK_SET);
+        res = (rb->write(tfd, preferences_buf, preferences_buf_size) >= 0);
+        rb->close(tfd);
+        return res;
+    }
+
+
     if (!rb->file_exists(TV_SETTINGS_FILE))
         tv_convert_settings_file();
 
+    
+    /* Try appending preferences */
+    if ( (stored_preferences_offset == 0) &&
+         ( (tfd = rb->open(TV_SETTINGS_FILE, O_RDWR)) >= 0) )
+    {
+        DEBUGF("Saving preferences: appending\n");
+        rb->lseek(tfd, 0, SEEK_END);
+        if (rb->write(tfd, preferences_buf, preferences_buf_size) < 0)
+            return false;
+
+        rb->lseek(tfd, TV_SETTINGS_HEADER_SIZE, SEEK_SET);
+        rb->read(tfd, buf, 2);
+        fcount = (buf[0] << 8) | buf[1];
+        fcount ++;
+        buf[0] = fcount >> 8;
+        buf[1] = fcount;
+        rb->lseek(tfd, TV_SETTINGS_HEADER_SIZE, SEEK_SET);
+        res = rb->write(tfd, buf, 2) >= 0;
+
+        rb->close(tfd);
+        return res;
+    }
+
     /* create header for the temporary file */
     rb->memcpy(buf, TV_SETTINGS_HEADER, TV_SETTINGS_HEADER_SIZE - 1);
     buf[TV_SETTINGS_HEADER_SIZE - 1] = TV_SETTINGS_VERSION;
@@ -539,12 +593,13 @@ bool tv_save_settings(void)
                     rb->lseek(ofd, size, SEEK_CUR);
                 else
                 {
-                    if ((rb->write(tfd, buf, MAX_PATH + 2) < 0) ||
-                        (!tv_copy_settings(ofd, tfd, size)))
+                    if ((rb->read(ofd, buf + (MAX_PATH + 2), size) < 0) ||
+                        (rb->write(tfd, buf, size + MAX_PATH + 2) < 0))
                     {
                         res = false;
                         break;
                     }
+                    new_fcount++;
                 }
             }
         }
@@ -555,31 +610,15 @@ bool tv_save_settings(void)
     {
         /* save to current read file's preferences and bookmarks */
         res = false;
-        rb->memset(buf, 0, MAX_PATH);
-        rb->strlcpy(buf, preferences->file_name, MAX_PATH);
 
-        if (rb->write(tfd, buf, MAX_PATH + 2) >= 0)
+        if (rb->write(tfd, preferences_buf, preferences_buf_size) >= 0)
         {
-            if (tv_write_preferences(tfd, preferences))
-            {
-                size = tv_serialize_bookmarks(tfd);
-                if (size > 0)
-                {
-                    size += TV_PREFERENCES_SIZE;
-                    rb->lseek(tfd, -size - 2, SEEK_CUR);
-                    buf[0] = size >> 8;
-                    buf[1] = size;
-                    if (rb->write(tfd, buf, 2) >= 0)
-                    {
-                        rb->lseek(tfd, TV_SETTINGS_HEADER_SIZE, SEEK_SET);
+            rb->lseek(tfd, TV_SETTINGS_HEADER_SIZE, SEEK_SET);
 
-                        fcount++;
-                        buf[0] = fcount >> 8;
-                        buf[1] = fcount;
-                        res = (rb->write(tfd, buf, 2) >= 0);
-                    }
-                }
-            }
+            new_fcount++;
+            buf[0] = new_fcount >> 8;
+            buf[1] = new_fcount;
+            res = (rb->write(tfd, buf, 2) >= 0);
         }
     }
     rb->close(tfd);
diff --git a/apps/plugins/text_viewer/tv_settings.h b/apps/plugins/text_viewer/tv_settings.h
index 65b31ec..afcf532 100644
--- a/apps/plugins/text_viewer/tv_settings.h
+++ b/apps/plugins/text_viewer/tv_settings.h
@@ -63,6 +63,7 @@ bool tv_load_settings(const unsigned char *file_name);
 
 /*
  * save the settings at each file
+ * supposed to be called only once at plugin exit
  *
  * return
  *     true  success
diff --git a/docs/CREDITS b/docs/CREDITS
index 422a228..54f21ca 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -573,7 +573,7 @@ William Peters
 Li Jie
 Cristina Talpiga
 Ştefan Moisei
-
+Alexander Meshcheryakov
 
 The libmad team
 The wavpack team