Implementation of a IsoStream to read from a memory buffer.

src/fsource.h

@@ -22,6 +22,7 @@
 #define ISO_LOCAL_FS_ID        1
 #define ISO_IMAGE_FS_ID        2
 #define ISO_ELTORITO_FS_ID     3
+#define ISO_MEM_FS_ID          4
 
 typedef struct Iso_File_Source IsoFileSource;
 typedef struct Iso_Filesystem IsoFilesystem;

src/stream.c

@@ -10,11 +10,13 @@
 #include "stream.h"
 #include "fsource.h"
 #include "error.h"
+#include "util.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 ino_t serial_id = (ino_t)1;
+ino_t mem_serial_id = (ino_t)1;
 
 typedef struct
 {
@@ -201,6 +203,160 @@ int iso_file_source_stream_new(IsoFileSource *src, IsoStream **stream)
     return ISO_SUCCESS;
 }
 
+
+
+typedef struct
+{
+    uint8_t *buf;
+    ssize_t offset; /* -1 if stream closed */
+    ino_t ino_id;
+    size_t size;
+} MemStreamData;
+
+static
+int mem_open(IsoStream *stream)
+{
+    MemStreamData *data;
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    data = (MemStreamData*)stream->data;
+    if (data->offset != -1) {
+        return ISO_FILE_ALREADY_OPENNED;
+    }
+    data->offset = 0;
+    return ISO_SUCCESS;
+}
+
+static
+int mem_close(IsoStream *stream)
+{
+    MemStreamData *data;
+    if (stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    data = (MemStreamData*)stream->data;
+    if (data->offset == -1) {
+        return ISO_FILE_NOT_OPENNED;
+    }
+    data->offset = -1;
+    return ISO_SUCCESS;
+}
+
+static
+off_t mem_get_size(IsoStream *stream)
+{
+    MemStreamData *data;
+    data = (MemStreamData*)stream->data;
+
+    return (off_t)data->size;
+}
+
+static
+int mem_read(IsoStream *stream, void *buf, size_t count)
+{
+    size_t len;
+    MemStreamData *data;
+    if (stream == NULL || buf == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    if (count == 0) {
+        return ISO_WRONG_ARG_VALUE;
+    }
+    data = stream->data;
+    
+    if (data->offset == -1) {
+        return ISO_FILE_NOT_OPENNED;
+    }
+    
+    len = MIN(count, data->size - data->offset);
+    memcpy(buf, data->buf + data->offset, len);
+    return len;
+}
+
+static
+int mem_is_repeatable(IsoStream *stream)
+{
+    return 1;
+}
+
+static
+void mem_get_id(IsoStream *stream, unsigned int *fs_id, dev_t *dev_id,
+                ino_t *ino_id)
+{
+    MemStreamData *data;
+    data = (MemStreamData*)stream->data;
+    *fs_id = ISO_MEM_FS_ID;
+    *dev_id = 0;
+    *ino_id = data->ino_id;
+}
+
+static
+char *mem_get_name(IsoStream *stream)
+{
+    return strdup("[MEMORY SOURCE]");
+}
+
+static
+void mem_free(IsoStream *stream)
+{
+    MemStreamData *data;
+    data = (MemStreamData*)stream->data;
+    free(data->buf);
+    free(data);
+}
+
+IsoStreamIface mem_stream_class = {
+    mem_open,
+    mem_close,
+    mem_get_size,
+    mem_read,
+    mem_is_repeatable,
+    mem_get_id,
+    mem_get_name,
+    mem_free
+};
+
+/**
+ * Create a stream for reading from a arbitrary memory buffer.
+ * When the Stream refcount reach 0, the buffer is free(3).
+ * 
+ * @return
+ *      1 sucess, < 0 error
+ */
+int iso_memory_stream_new(unsigned char *buf, size_t size, IsoStream **stream)
+{
+    IsoStream *str;
+    MemStreamData *data;
+
+    if (buf == NULL || stream == NULL) {
+        return ISO_NULL_POINTER;
+    }
+
+    str = malloc(sizeof(IsoStream));
+    if (str == NULL) {
+        return ISO_MEM_ERROR;
+    }
+    data = malloc(sizeof(MemStreamData));
+    if (str == NULL) {
+        free(str);
+        return ISO_MEM_ERROR;
+    }
+
+    /* fill data */
+    data->buf = buf;
+    data->size = size;
+    data->offset = -1;
+    data->ino_id = mem_serial_id++;
+
+    str->refcount = 1;
+    str->data = data;
+    str->class = &mem_stream_class;
+
+    *stream = str;
+    return ISO_SUCCESS;
+}
+
 void iso_stream_ref(IsoStream *stream)
 {
     ++stream->refcount;

src/stream.h

@@ -162,4 +162,13 @@ char *iso_stream_get_name(IsoStream *stream)
  */
 int iso_file_source_stream_new(IsoFileSource *src, IsoStream **stream);
 
+/**
+ * Create a stream for reading from a arbitrary memory buffer.
+ * When the Stream refcount reach 0, the buffer is free(3).
+ * 
+ * @return
+ *      1 sucess, < 0 error
+ */
+int iso_memory_stream_new(unsigned char *buf, size_t size, IsoStream **stream);
+
 #endif /*STREAM_H_*/