Add support for cut-out files.

libisofs/builder.c

@@ -52,12 +52,13 @@ int default_create_file(IsoNodeBuilder *builder, IsoImage *image,
     if (ret < 0) {
         return ret;
     }
+
+    /* take a ref to the src, as stream has taken our ref */
+    iso_file_source_ref(src);
     
     name = iso_file_source_get_name(src);
     ret = iso_node_new_file(name, stream, &node);
     if (ret < 0) {
-        /* the stream has taken our ref to src, so we need to add one */
-        iso_file_source_ref(src);
         iso_stream_unref(stream);
         free(name);
         return ret;

libisofs/builder.h

@@ -34,8 +34,7 @@ struct Iso_Node_Builder
      * In that case, if the implementation can't do the conversion, it
      * should fail propertly.
      * 
-     * On sucess, the ref. to src will be owned by file, so you musn't
-     * unref it.
+     * Note that the src is never unref, so you need to free it.
      * 
      * @return
      *    1 on success, < 0 on error

libisofs/libisofs.h

@@ -2805,6 +2805,44 @@ int iso_tree_add_node(IsoImage *image, IsoDir *parent, const char *path,
 int iso_tree_add_new_node(IsoImage *image, IsoDir *parent, const char *name, 
                           const char *path, IsoNode **node);
 
+/**
+ * Add a new node to the image tree, from an existing file, and with the
+ * given name, that must not exist on dir. The node will be cut-out to the
+ * submitted size, and its contents will be read from the given offset. This
+ * function is thus suitable for adding only a piece of a file to the image.
+ * 
+ * @param image
+ *      The image
+ * @param parent
+ *      The directory in the image tree where the node will be added.
+ * @param name
+ *      The name that the node will have on image.
+ * @param path
+ *      The path of the file to add in the filesystem. For now only regular
+ *      files and symlinks to regular files are supported.
+ * @param offset
+ *      Offset on the given file from where to start reading data.
+ * @param size
+ *      Max size of the file.
+ * @param node
+ *      place where to store a pointer to the newly added file. No 
+ *      extra ref is addded, so you will need to call iso_node_ref() if you 
+ *      really need it. You can pass NULL in this parameter if you don't need 
+ *      the pointer.
+ * @return
+ *     number of nodes in parent if success, < 0 otherwise
+ *     Possible errors:
+ *         ISO_NULL_POINTER, if image, parent or path are NULL
+ *         ISO_NODE_NAME_NOT_UNIQUE, a node with same name already exists
+ *         ISO_OUT_OF_MEM
+ * 
+ * @since 0.6.4
+ */
+int iso_tree_add_new_cut_out_node(IsoImage *image, IsoDir *parent, 
+                                  const char *name, const char *path, 
+                                  off_t offset, off_t size,
+                                  IsoNode **node);
+
 /**
  * Add the contents of a dir to a given directory of the iso tree.
  * 
@@ -3639,10 +3677,16 @@ void iso_stream_get_id(IsoStream *stream, unsigned int *fs_id, dev_t *dev_id,
 
 /** 
  * File path break specification constraints and will be ignored 
- * (HINT,MEDIUM, -141) 
+ * (HINT,MEDIUM, -144) 
  */
 #define ISO_FILE_IMGPATH_WRONG          0xC020FF70
 
+/** 
+ * Offset greater than file size (FAILURE,HIGH, -145) 
+ * @since 0.6.4
+ */
+#define ISO_FILE_OFFSET_TOO_BIG         0xE830FF6A
+
 /** Charset conversion error (FAILURE,HIGH, -256) */
 #define ISO_CHARSET_CONV_ERROR          0xE830FF00
 

libisofs/stream.c

@@ -17,6 +17,7 @@
 
 ino_t serial_id = (ino_t)1;
 ino_t mem_serial_id = (ino_t)1;
+ino_t cut_out_serial_id = (ino_t)1;
 
 typedef struct
 {
@@ -175,7 +176,7 @@ int iso_file_source_stream_new(IsoFileSource *src, IsoStream **stream)
         return ISO_OUT_OF_MEM;
     }
     data = malloc(sizeof(FSrcStreamData));
-    if (str == NULL) {
+    if (data == NULL) {
         free(str);
         return ISO_OUT_OF_MEM;
     }
@@ -212,6 +213,193 @@ int iso_file_source_stream_new(IsoFileSource *src, IsoStream **stream)
     return ISO_SUCCESS;
 }
 
+struct cut_out_stream
+{
+    IsoFileSource *src;
+
+    /* key for file identification inside filesystem */
+    dev_t dev_id;
+    ino_t ino_id;
+    off_t offset; /**< offset where read begins */
+    off_t size; /**< size of this file */
+    off_t pos; /* position on the file for read */
+};
+
+static
+int cut_out_open(IsoStream *stream)
+{
+    int ret;
+    struct stat info;
+    IsoFileSource *src;
+    struct cut_out_stream *data;
+    
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    
+    data = stream->data;
+    src = data->src;
+    ret = iso_file_source_stat(data->src, &info);
+    if (ret < 0) {
+        return ret;
+    }
+    ret = iso_file_source_open(src);
+    if (ret < 0) {
+        return ret;
+    }
+    
+    {
+        off_t ret;
+        if (data->offset > info.st_size) {
+            /* file is smaller than expected */
+            ret = iso_file_source_lseek(src, info.st_size, 0);
+        } else {
+            ret = iso_file_source_lseek(src, data->offset, 0);
+        }
+        if (ret < 0) {
+            return (int) ret;
+        }
+    }
+    data->pos = 0;
+    if (data->offset + data->size > info.st_size) {
+        return 3; /* file smaller than expected */
+    } else {
+        return ISO_SUCCESS;
+    }
+}
+
+static
+int cut_out_close(IsoStream *stream)
+{
+    IsoFileSource *src;
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    src = ((struct cut_out_stream*)stream->data)->src;
+    return iso_file_source_close(src);
+}
+
+static
+off_t cut_out_get_size(IsoStream *stream)
+{
+    struct cut_out_stream *data = stream->data;
+    return data->size;
+}
+
+static
+int cut_out_read(IsoStream *stream, void *buf, size_t count)
+{
+    struct cut_out_stream *data = stream->data;
+    count = (size_t)MIN(data->size - data->pos, count);
+    if (count == 0) {
+        return 0;
+    }
+    return iso_file_source_read(data->src, buf, count);
+}
+
+static
+int cut_out_is_repeatable(IsoStream *stream)
+{
+    /* reg files are always repeatable */
+    return 1;
+}
+
+static
+void cut_out_get_id(IsoStream *stream, unsigned int *fs_id, dev_t *dev_id,
+                ino_t *ino_id)
+{
+    FSrcStreamData *data;
+    IsoFilesystem *fs;
+    
+    data = (FSrcStreamData*)stream->data;
+    fs = iso_file_source_get_filesystem(data->src);
+
+    *fs_id = fs->get_id(fs);
+    *dev_id = data->dev_id;
+    *ino_id = data->ino_id;
+}
+
+static
+void cut_out_free(IsoStream *stream)
+{
+    struct cut_out_stream *data = stream->data;
+    iso_file_source_unref(data->src);
+    free(data);
+}
+
+IsoStreamIface cut_out_stream_class = {
+    0,
+    "cout",
+    cut_out_open,
+    cut_out_close,
+    cut_out_get_size,
+    cut_out_read,
+    cut_out_is_repeatable,
+    cut_out_get_id,
+    cut_out_free
+};
+
+int iso_cut_out_stream_new(IsoFileSource *src, off_t offset, off_t size, 
+                           IsoStream **stream)
+{
+    int r;
+    struct stat info;
+    IsoStream *str;
+    struct cut_out_stream *data;
+
+    if (src == NULL || stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    if (size == 0) {
+        return ISO_WRONG_ARG_VALUE;
+    }
+
+    r = iso_file_source_stat(src, &info);
+    if (r < 0) {
+        return r;
+    }
+    if (!S_ISREG(info.st_mode)) {
+        return ISO_WRONG_ARG_VALUE;
+    }
+    if (offset > info.st_size) {
+        return ISO_FILE_OFFSET_TOO_BIG;
+    }
+    
+    /* check for read access to contents */
+    r = iso_file_source_access(src);
+    if (r < 0) {
+        return r;
+    }
+
+    str = malloc(sizeof(IsoStream));
+    if (str == NULL) {
+        return ISO_OUT_OF_MEM;
+    }
+    data = malloc(sizeof(struct cut_out_stream));
+    if (data == NULL) {
+        free(str);
+        return ISO_OUT_OF_MEM;
+    }
+
+    /* take a new ref to IsoFileSource */
+    data->src = src;
+    iso_file_source_ref(src);
+    
+    data->offset = offset;
+    data->size = MIN(info.st_size - offset, size);
+    
+    /* get the id numbers */
+    data->dev_id = (dev_t) 0;
+    data->ino_id = cut_out_serial_id++;
+
+    str->refcount = 1;
+    str->data = data;
+    str->class = &cut_out_stream_class;
+
+    *stream = str;
+    return ISO_SUCCESS;
+}
+
 
 
 typedef struct

libisofs/stream.h

@@ -33,6 +33,16 @@ void iso_stream_get_file_name(IsoStream *stream, char *name);
  */
 int iso_file_source_stream_new(IsoFileSource *src, IsoStream **stream);
 
+/**
+ * Create a new stream to read a chunk of an IsoFileSource..
+ * The stream will add a ref. to the IsoFileSource.
+ * 
+ * @return
+ *      1 sucess, < 0 error
+ */
+int iso_cut_out_stream_new(IsoFileSource *src, off_t offset, off_t size, 
+                           IsoStream **stream);
+
 /**
  * Create a stream for reading from a arbitrary memory buffer.
  * When the Stream refcount reach 0, the buffer is free(3).

libisofs/tree.c

@@ -582,13 +582,14 @@ int iso_tree_add_new_node(IsoImage *image, IsoDir *parent, const char *name,
     }
 
     result = image->builder->create_node(image->builder, image, file, &new);
-    if (result < 0) {
-        return result;
-    }
     
     /* free the file */
     iso_file_source_unref(file);
     
+    if (result < 0) {
+        return result;
+    }
+    
     result = iso_node_set_name(new, name);
     if (result < 0) {
         iso_node_unref(new);
@@ -603,6 +604,85 @@ int iso_tree_add_new_node(IsoImage *image, IsoDir *parent, const char *name,
     return iso_dir_insert(parent, new, pos, ISO_REPLACE_NEVER);
 }
 
+int iso_tree_add_new_cut_out_node(IsoImage *image, IsoDir *parent, 
+                                  const char *name, const char *path, 
+                                  off_t offset, off_t size,
+                                  IsoNode **node)
+{
+    int result;
+    struct stat info;
+    IsoFilesystem *fs;
+    IsoFileSource *src;
+    IsoFile *new;
+    IsoNode **pos;
+    IsoStream *stream;
+
+    if (image == NULL || parent == NULL || name == NULL || path == NULL) {
+        return ISO_NULL_POINTER;
+    }
+
+    if (node) {
+        *node = NULL;
+    }
+
+    /* find place where to insert */
+    result = iso_dir_exists(parent, name, &pos);
+    if (result) {
+        /* a node with same name already exists */
+        return ISO_NODE_NAME_NOT_UNIQUE;
+    }
+
+    fs = image->fs;
+    result = fs->get_by_path(fs, path, &src);
+    if (result < 0) {
+        return result;
+    }
+
+    result = iso_file_source_stat(src, &info);
+    if (result < 0) {
+        iso_file_source_unref(src);
+        return result;
+    }
+    if (!S_ISREG(info.st_mode)) {
+        return ISO_WRONG_ARG_VALUE;
+    }
+    if (offset >= info.st_size) {
+        return ISO_WRONG_ARG_VALUE;
+    }
+
+    /* force regular file */
+    result = image->builder->create_file(image->builder, image, src, &new);
+    
+    /* free the file */
+    iso_file_source_unref(src);
+    
+    if (result < 0) {
+        return result;
+    }
+    
+    /* replace file iso stream with a cut-out-stream */
+    result = iso_cut_out_stream_new(src, offset, size, &stream);
+    if (result < 0) {
+        iso_node_unref((IsoNode*)new);
+        return result;
+    }
+    iso_stream_unref(new->stream);
+    new->stream = stream;
+    
+    result = iso_node_set_name((IsoNode*)new, name);
+    if (result < 0) {
+        iso_node_unref((IsoNode*)new);
+        return result;
+    }
+
+    if (node) {
+        *node = (IsoNode*)new;
+    }
+
+    /* finally, add node to parent */
+    return iso_dir_insert(parent, (IsoNode*)new, pos, ISO_REPLACE_NEVER);
+}
+
 static
 int check_excludes(IsoImage *image, const char *path)
 {