Add new file IO callback API.

include/libchdr/chd.h

@@ -255,6 +255,9 @@ extern "C" {
 /* A/V laserdisc frame metadata */
 #define AV_LD_METADATA_TAG			CHD_MAKE_TAG('A','V','L','D')
 
+/* DVD metadata */
+#define DVD_METADATA_TAG			CHD_MAKE_TAG('D','V','D',' ')
+
 /* CHD open values */
 #define CHD_OPEN_READ				1
 #define CHD_OPEN_READWRITE			2
@@ -375,7 +378,8 @@ struct _chd_verify_result
 /* chd_error chd_create_file(core_file *file, uint64_t logicalbytes, uint32_t hunkbytes, uint32_t compression, chd_file *parent); */
 
 /* open an existing CHD file */
-CHD_EXPORT chd_error chd_open_core_file(core_file *file, int mode, chd_file *parent, chd_file **chd);
+CHD_EXPORT chd_error chd_open_core_file_callbacks(const core_file_callbacks *callbacks, const void *user_data, int mode, chd_file *parent, chd_file **chd);
+CHD_EXPORT chd_error chd_open_core_file(core_file *file, int mode, chd_file *parent, chd_file **chd); /* Legacy; use chd_open_core_file_callbacks instead! */
 CHD_EXPORT chd_error chd_open_file(FILE *file, int mode, chd_file *parent, chd_file **chd);
 CHD_EXPORT chd_error chd_open(const char *filename, int mode, chd_file *parent, chd_file **chd);
 
@@ -399,7 +403,8 @@ CHD_EXPORT const char *chd_error_string(chd_error err);
 CHD_EXPORT const chd_header *chd_get_header(chd_file *chd);
 
 /* read CHD header data from file into the pointed struct */
-CHD_EXPORT chd_error chd_read_header_core_file(core_file *file, chd_header *header);
+CHD_EXPORT chd_error chd_read_header_core_file_callbacks(const core_file_callbacks *callback, const void *user_data, chd_header *header);
+CHD_EXPORT chd_error chd_read_header_core_file(core_file *file, chd_header *header); /* Legacy; use chd_read_header_core_file_callbacks instead! */
 CHD_EXPORT chd_error chd_read_header_file(FILE *file, chd_header *header);
 CHD_EXPORT chd_error chd_read_header(const char *filename, chd_header *header);
 

include/libchdr/coretypes.h

@@ -16,12 +16,7 @@
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
 #endif
 
-typedef struct chd_core_file {
-	/*
-	 * arbitrary pointer to data the implementation uses to implement the below functions
-	 */
-	void *argp;
-
+typedef struct chd_core_file_callbacks {
 	/*
 	 * return the size of a given file as a 64-bit unsigned integer.
 	 * the position of the file pointer after calling this function is
@@ -30,36 +25,57 @@ typedef struct chd_core_file {
 	 *
 	 * on error, (uint64_t)-1 is returned.
 	 */
-	uint64_t(*fsize)(struct chd_core_file*);
+	uint64_t(*fsize)(void*);
 
 	/*
 	 * should match the behavior of fread, except the FILE* argument at the end
-	 * will be replaced with a struct chd_core_file*.
+	 * will be replaced with a void*.
 	 */
-	size_t(*fread)(void*,size_t,size_t,struct chd_core_file*);
+	size_t(*fread)(void*,size_t,size_t,void*);
 
 	// closes the given file.
-	int (*fclose)(struct chd_core_file*);
+	int (*fclose)(void*);
 
 	// fseek clone
+	int (*fseek)(void*, int64_t, int);
+} core_file_callbacks;
+
+typedef struct chd_core_file_callbacks_and_argp {
+	const core_file_callbacks *callbacks;
+
+	/*
+	 * arbitrary pointer to data the implementation uses to implement the above functions
+	 */
+	void *argp;
+} core_file_callbacks_and_argp;
+
+/* Legacy API */
+
+typedef struct chd_core_file {
+	void *argp;
+	uint64_t(*fsize)(struct chd_core_file*);
+	size_t(*fread)(void*,size_t,size_t,struct chd_core_file*);
+	int (*fclose)(struct chd_core_file*);
 	int (*fseek)(struct chd_core_file*, int64_t, int);
 } core_file;
 
-static inline int core_fclose(core_file *fp) {
-	return fp->fclose(fp);
+/* File IO shortcuts */
+
+static inline int core_fclose(const core_file_callbacks_and_argp *fp) {
+	return fp->callbacks->fclose(fp->argp);
 }
 
-static inline size_t core_fread(core_file *fp, void *ptr, size_t len) {
-	return fp->fread(ptr, 1, len, fp);
+static inline size_t core_fread(const core_file_callbacks_and_argp *fp, void *ptr, size_t len) {
+	return fp->callbacks->fread(ptr, 1, len, fp->argp);
 }
 
-static inline int core_fseek(core_file* fp, int64_t offset, int whence) {
-	return fp->fseek(fp, offset, whence);
+static inline int core_fseek(const core_file_callbacks_and_argp* fp, int64_t offset, int whence) {
+	return fp->callbacks->fseek(fp->argp, offset, whence);
 }
 
-static inline uint64_t core_fsize(core_file *fp)
+static inline uint64_t core_fsize(const core_file_callbacks_and_argp *fp)
 {
-	return fp->fsize(fp);
+	return fp->callbacks->fsize(fp->argp);
 }
 
 #endif

src/libchdr_cdrom.c

@@ -4,7 +4,7 @@
 
     cdrom.c
 
-    Generic MAME CD-ROM utilties - build IDE and SCSI CD-ROMs on top of this
+    Generic MAME CD-ROM utilities - build IDE and SCSI CD-ROMs on top of this
 
 ****************************************************************************