Adding image cache.

include/openmg/database.h

@@ -16,7 +16,7 @@ mg_database_prepare (MgDatabase *self, char *z_sql, const char **pz_tail);
 int
 mg_database_get_affected_rows (MgDatabase *self);
 
-char *
+const char *
 mg_database_get_error_string (MgDatabase *self);
 
 G_END_DECLS

include/openmg/database/migrations.h

@@ -3,7 +3,7 @@ const char *const MIGRATIONS[] = {
     "key TEXT PRIMARY KEY,\n"
     "value TEXT\n"
     ");\n"),
-    ("CREATE TABLE image (\n"
+    ("CREATE TABLE images (\n"
     "url TEXT PRIMARY KEY,\n"
     "file TEXT\n"
     ");\n"),

include/openmg/database/statement.h

@@ -8,8 +8,19 @@ G_DECLARE_FINAL_TYPE (MgDatabaseStatement, mg_database_statement, MG, DATABASE_S
 
 MgDatabaseStatement *mg_database_statement_new ();
 
-void
-mg_database_statement_bind_text (MgDatabaseStatement *self, int index, char *value);
+int
+mg_database_statement_bind_text (MgDatabaseStatement *self,
+        int index, const char *value);
+int
+mg_database_statement_step (MgDatabaseStatement *self);
+
+const unsigned char *
+mg_database_statement_column_text (MgDatabaseStatement *self,
+        int i_col);
+
+int
+mg_database_statement_column_int (MgDatabaseStatement *self,
+        int i_col);
 
 G_END_DECLS
 

src/database/statement.c

@@ -13,7 +13,7 @@ struct _MgDatabaseStatement {
 G_DEFINE_TYPE (MgDatabaseStatement, mg_database_statement, G_TYPE_OBJECT)
 
 typedef enum {
-    MG_DATABASE_STATEMENT_OWNER,
+    MG_DATABASE_STATEMENT_OWNER = 1,
     MG_DATABASE_STATEMENT_STMT,
     MG_DATABASE_STATEMENT_N_PROPERTIES
 } MgDatabaseStatementProperties;
@@ -38,7 +38,7 @@ MgDatabaseStatement *
 mg_database_statement_new (MgDatabase *owner, sqlite3_stmt *statement) {
     MgDatabaseStatement *self = NULL;
     self = MG_DATABASE_STATEMENT ((g_object_new (MG_TYPE_DATABASE_STATEMENT,
-                    "owner", owner, "stmt", statement)));
+                    "owner", owner, "stmt", statement, NULL)));
     return self;
 }
 
@@ -52,7 +52,7 @@ mg_database_statement_class_init (MgDatabaseStatementClass *class) {
             "owner",
             "Owner",
             "Owner MgDatabase.",
-            MG_TYPE_DATABASE_STATEMENT,
+            MG_TYPE_DATABASE,
             G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
     database_statement_properties[MG_DATABASE_STATEMENT_STMT] = g_param_spec_pointer (
             "stmt",
@@ -95,6 +95,7 @@ mg_database_statement_set_property (GObject *object,
                 g_clear_object (&(self->owner));
             }
             self->owner = g_value_peek_pointer (value);
+            g_object_ref (self->owner);
             break;
         case MG_DATABASE_STATEMENT_STMT:
             if (self->stmt) {
@@ -124,17 +125,47 @@ mg_database_statement_get_stmt (MgDatabaseStatement *self) {
 static void
 mg_database_statement_dispose (GObject *object) {
     MgDatabaseStatement *self = MG_DATABASE_STATEMENT (object);
-    g_clear_object (&(self->owner));
+    if (self->owner) {
+        g_clear_object (&(self->owner));
+    }
     sqlite3_finalize (self->stmt);
 }
 
-void
-mg_database_statement_bind_text (MgDatabaseStatement *self, int index, char *value) {
+int
+mg_database_statement_bind_text (MgDatabaseStatement *self,
+        int index, const char *value) {
     sqlite3_stmt *stmt = mg_database_statement_get_stmt (self);
     int error = sqlite3_bind_text (stmt, index, value, -1, SQLITE_TRANSIENT);
     if ( error != SQLITE_OK ) {
         g_error (mg_database_get_error_string (self->owner));
     }
+    return error;
+}
+
+int
+mg_database_statement_step (MgDatabaseStatement *self) {
+    sqlite3_stmt *stmt = mg_database_statement_get_stmt (self);
+    int error;
+    while ((error = sqlite3_step (stmt)) == SQLITE_BUSY) {
+    }
+    if (error != SQLITE_DONE && error != SQLITE_ROW) {
+        g_error (mg_database_get_error_string (self->owner));
+    }
+    return error;
+}
+
+const unsigned char *
+mg_database_statement_column_text (MgDatabaseStatement *self,
+        int i_col) {
+    sqlite3_stmt *stmt = mg_database_statement_get_stmt (self);
+    return sqlite3_column_text (stmt, i_col);
+}
+
+int
+mg_database_statement_column_int (MgDatabaseStatement *self,
+        int i_col) {
+    sqlite3_stmt *stmt = mg_database_statement_get_stmt (self);
+    return sqlite3_column_int (stmt, i_col);
 }
 
 static void

src/view/picture.c

@@ -1,38 +1,57 @@
 #include <stdio.h>
 
+#include <glib.h>
 #include <gtk/gtk.h>
+#include <sqlite3.h>
 
 #include <openmg/util/soup.h>
 #include <openmg/util/gobject_utility_extensions.h>
 
+#include <openmg/database.h>
+#include <openmg/database/statement.h>
+
+const char *const IMAGE_CACHE_FORMAT_STRING =
+"%s/.cache/openmg/%s";
+
+static char *
+generate_cache_file_name (void);
+GFile *
+get_image_for_url (const char *url);
+
 GtkPicture *
 create_picture_from_url (const char *const url, gint picture_size) {
     GtkPicture *picture = NULL;
-    GFileIOStream *iostream;
-    GFile *tmp_image;
+    GFileIOStream *iostream = NULL;
+    GFile *image = NULL;
     GError *error = NULL;
-    GdkTexture *texture;
+    GdkTexture *texture = NULL;
 
     size_t size_downloaded_image = 0;
-    char *downloaded_image;
+    char *downloaded_image = NULL;
 
     MgUtilSoup *util_soup = mg_util_soup_new ();
-    downloaded_image = mg_util_soup_get_request (util_soup,
-            url, &size_downloaded_image);
-    tmp_image = g_file_new_tmp ("mangareadertmpfileXXXXXX", &iostream, &error);
-    if (error) {
-        fprintf (stderr, "Unable to read file: %s\n", error->message);
-        g_clear_error (&error);
-        goto cleanup_create_picture_from_url;
+    image = get_image_for_url (url);
+    if (!g_file_query_exists (image, NULL)) {
+        downloaded_image =
+            mg_util_soup_get_request
+            (util_soup,
+             url, &size_downloaded_image);
+        iostream = g_file_create_readwrite (image, G_FILE_CREATE_NONE,
+                NULL, &error);
+        if (error) {
+            fprintf (stderr, "Unable to read file: %s\n", error->message);
+            g_clear_error (&error);
+            goto cleanup_create_picture_from_url;
+        }
+        g_output_stream_write (g_io_stream_get_output_stream (G_IO_STREAM (iostream)),
+                downloaded_image, size_downloaded_image, NULL, &error);
+        if (error) {
+            fprintf (stderr, "Unable to write file: %s\n", error->message);
+            g_clear_error (&error);
+            goto cleanup_create_picture_from_url;
+        }
     }
-    g_output_stream_write (g_io_stream_get_output_stream (G_IO_STREAM (iostream)),
-            downloaded_image, size_downloaded_image, NULL, &error);
-    if (error) {
-        fprintf (stderr, "Unable to write file: %s\n", error->message);
-        g_clear_error (&error);
-        goto cleanup_create_picture_from_url;
-    }
-    texture = gdk_texture_new_from_file (tmp_image, &error);
+    texture = gdk_texture_new_from_file (image, &error);
     if (error) {
         fprintf (stderr, "Texture malformed.");
         goto cleanup_create_picture_from_url;
@@ -42,9 +61,67 @@ create_picture_from_url (const char *const url, gint picture_size) {
     g_object_set_property_int (G_OBJECT(picture), "width-request", picture_size);
 
 cleanup_create_picture_from_url:
-    g_free (downloaded_image);
+    if (downloaded_image) {
+        g_free (downloaded_image);
+    }
     g_clear_object (&util_soup);
-    g_clear_object (&iostream);
-    g_clear_object (&tmp_image);
+    if (iostream) {
+        g_clear_object (&iostream);
+    }
+    g_clear_object (&image);
     return picture;
 }
+
+GFile *
+get_image_for_url (const char *url) {
+    GFile *image;
+    MgDatabase *db = mg_database_new ();
+    MgDatabaseStatement *statement = mg_database_prepare (db,
+            "select file from images where url = ?;", NULL);
+    char *file_name = NULL;
+    mg_database_statement_bind_text (statement, 1, url);
+    if (mg_database_statement_step (statement) == SQLITE_ROW) {
+        const char *file_name = (const char *) mg_database_statement_column_text
+            (statement, 0);
+        image = g_file_new_for_path (file_name);
+        goto cleanup_get_image_for_url;
+    }
+    g_clear_object (&statement);
+    file_name = generate_cache_file_name ();
+    statement = mg_database_prepare (db,
+            "insert into images (url, file) values (?, ?);", NULL); 
+    mg_database_statement_bind_text (statement, 1, url);
+    mg_database_statement_bind_text (statement, 2, file_name);
+    mg_database_statement_step (statement);
+    image = g_file_new_for_path (file_name);
+cleanup_get_image_for_url:
+    if (file_name) {
+        g_free (file_name);
+    }
+    g_clear_object (&statement);
+    g_clear_object (&db);
+    return image;
+}
+
+static char *
+generate_cache_file_name (void) {
+    const char *home_dir = g_get_home_dir();
+    char *file_basename = g_uuid_string_random ();
+    char *file_path;
+    char *file_path_directory;
+    size_t file_path_len;
+    file_path_len = snprintf
+        (NULL, 0, IMAGE_CACHE_FORMAT_STRING,
+         home_dir, file_basename);
+    file_path = g_malloc
+        (sizeof *file_path
+         * (file_path_len + 1));
+    snprintf (file_path, file_path_len,
+            IMAGE_CACHE_FORMAT_STRING,
+            home_dir, file_basename);
+    file_path_directory = g_path_get_dirname
+        (file_path);
+    g_mkdir_with_parents
+        (file_path_directory, 00755);
+    return file_path;
+}