1 files changed, 349 insertions, 0 deletions
diff --git a/src/libexif/exif-loader.c b/src/libexif/exif-loader.c
new file mode 100644
index 0000000..d6eba7d
--- /dev/null
+++ b/src/libexif/exif-loader.c
@@ -0,0 +1,349 @@
+#include <config.h>
+
+#include <libexif/exif-loader.h>
+#include <libexif/i18n.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#undef JPEG_MARKER_SOI
+#define JPEG_MARKER_SOI  0xd8
+#undef JPEG_MARKER_APP0
+#define JPEG_MARKER_APP0 0xe0
+#undef JPEG_MARKER_APP1
+#define JPEG_MARKER_APP1 0xe1
+#undef JPEG_MARKER_APP13
+#define JPEG_MARKER_APP13 0xed
+#undef JPEG_MARKER_COM
+#define JPEG_MARKER_COM 0xfe
+
+typedef enum {
+	EL_READ = 0,
+	EL_READ_SIZE_BYTE_24,
+	EL_READ_SIZE_BYTE_16,
+	EL_READ_SIZE_BYTE_08,
+	EL_READ_SIZE_BYTE_00,
+	EL_SKIP_BYTES,
+	EL_EXIF_FOUND,
+} ExifLoaderState;
+
+typedef enum {
+	EL_DATA_FORMAT_UNKNOWN,
+	EL_DATA_FORMAT_EXIF,
+	EL_DATA_FORMAT_JPEG,
+	EL_DATA_FORMAT_FUJI_RAW
+} ExifLoaderDataFormat;
+
+struct _ExifLoader {
+	ExifLoaderState state;
+	ExifLoaderDataFormat data_format;
+
+	/* Small buffer used for detection of format */
+	unsigned char b[12];
+	unsigned char b_len;
+
+	unsigned int size;
+	unsigned char *buf;
+	unsigned int bytes_read;
+
+	unsigned int ref_count;
+
+	ExifLog *log;
+	ExifMem *mem;
+};
+
+static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
+
+static void *
+exif_loader_alloc (ExifLoader *l, unsigned int i)
+{
+	void *d;
+
+	if (!l || !i) return NULL;
+
+	d = exif_mem_alloc (l->mem, i);
+	if (d) return d;
+
+	EXIF_LOG_NO_MEMORY (l->log, "ExifLog", i);
+	return NULL;
+}
+
+#undef  MIN
+#define MIN(a, b)  (((a) < (b)) ? (a) : (b))
+
+void
+exif_loader_write_file (ExifLoader *l, const char *path)
+{
+	FILE *f;
+	int size;
+	unsigned char data[1024];
+
+	if (!l) return;
+
+	f = fopen (path, "rb");
+	if (!f) {
+		exif_log (l->log, EXIF_LOG_CODE_NONE, "ExifLoader",
+			  _("The file '%s' could not be opened."), path);
+		return;
+	}
+	while (1) {
+		size = fread (data, 1, sizeof (data), f);
+		if (size <= 0) break;
+		if (!exif_loader_write (l, data, size)) break;
+	}
+	fclose (f);
+}
+
+static unsigned int
+exif_loader_copy (ExifLoader *eld, unsigned char *buf, unsigned int len)
+{
+	if (!eld || (len && !buf) || (eld->bytes_read >= eld->size)) return 0;
+
+	/* If needed, allocate the buffer. */
+	if (!eld->buf) eld->buf = exif_loader_alloc (eld, eld->size);
+	if (!eld->buf) return 0;
+
+	/* Copy memory */
+	len = MIN (len, eld->size - eld->bytes_read);
+	memcpy (eld->buf + eld->bytes_read, buf, len);
+	eld->bytes_read += len;
+
+	return (eld->bytes_read >= eld->size) ? 0 : 1;
+}
+
+unsigned char
+exif_loader_write (ExifLoader *eld, unsigned char *buf, unsigned int len)
+{
+	unsigned int i;
+
+	if (!eld || (len && !buf)) return 0;
+
+	switch (eld->state) {
+	case EL_EXIF_FOUND:
+		return exif_loader_copy (eld, buf, len);
+	case EL_SKIP_BYTES:
+		if (eld->size > len) { eld->size -= len; return 1; }
+		len -= eld->size;
+		buf += eld->size;
+		eld->size = 0;
+		eld->b_len = 0;
+		switch (eld->data_format) {
+		case EL_DATA_FORMAT_FUJI_RAW:
+			eld->state = EL_READ_SIZE_BYTE_24;
+			break;
+		default:
+			eld->state = EL_READ;
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	exif_log (eld->log, EXIF_LOG_CODE_DEBUG, "ExifLoader",
+		  "Scanning %i byte(s) of data...", len);
+
+	/*
+	 * First fill the small buffer. Only continue if the buffer
+	 * is filled. Note that EXIF data contains at least 12 bytes.
+	 */
+	i = MIN (len, sizeof (eld->b) - eld->b_len);
+	if (i) {
+		memcpy (&eld->b[eld->b_len], buf, i);
+		eld->b_len += i;
+		if (eld->b_len < sizeof (eld->b)) return 1;
+		buf += i;
+		len -= i;
+	}
+
+	switch (eld->data_format) {
+	case EL_DATA_FORMAT_UNKNOWN:
+
+		/* Check the small buffer against known formats. */
+		if (!memcmp (eld->b, "FUJIFILM", 8)) {
+
+			/* Skip to byte 84. There is another offset there. */
+			eld->data_format = EL_DATA_FORMAT_FUJI_RAW;
+			eld->size = 84;
+			eld->state = EL_SKIP_BYTES;
+			eld->size = 84;
+
+		} else if (!memcmp (eld->b + 2, ExifHeader, sizeof (ExifHeader))) {
+
+			/* Read the size (2 bytes). */
+			eld->data_format = EL_DATA_FORMAT_EXIF;
+			eld->state = EL_READ_SIZE_BYTE_08;
+		}
+	default:
+		break;
+	}
+
+	for (i = 0; i < sizeof (eld->b); i++)
+		switch (eld->state) {
+		case EL_EXIF_FOUND:
+			if (!exif_loader_copy (eld, eld->b + i,
+					sizeof (eld->b) - i)) return 0;
+			return exif_loader_copy (eld, buf, len);
+		case EL_SKIP_BYTES:
+			eld->size--;
+			if (!eld->size) eld->state = EL_READ;
+			break;
+
+		case EL_READ_SIZE_BYTE_24:
+			eld->size |= eld->b[i] << 24;
+			eld->state = EL_READ_SIZE_BYTE_16;
+			break;
+		case EL_READ_SIZE_BYTE_16:
+			eld->size |= eld->b[i] << 16;
+			eld->state = EL_READ_SIZE_BYTE_08;
+			break;
+		case EL_READ_SIZE_BYTE_08:
+			eld->size |= eld->b[i] << 8;
+			eld->state = EL_READ_SIZE_BYTE_00;
+			break;
+		case EL_READ_SIZE_BYTE_00:
+			eld->size |= eld->b[i] << 0;
+			switch (eld->data_format) {
+			case EL_DATA_FORMAT_JPEG:
+				eld->state = EL_SKIP_BYTES;
+				eld->size -= 2;
+				break;
+			case EL_DATA_FORMAT_FUJI_RAW:
+				eld->data_format = EL_DATA_FORMAT_EXIF;
+				eld->state = EL_SKIP_BYTES;
+				eld->size -= 86;
+				break;
+			case EL_DATA_FORMAT_EXIF:
+				eld->state = EL_EXIF_FOUND;
+				break;
+			default:
+				break;
+			}
+			break;
+
+		default:
+			switch (eld->b[i]) {
+			case JPEG_MARKER_APP1:
+				eld->data_format = EL_DATA_FORMAT_EXIF;
+				eld->size = 0;
+				eld->state = EL_READ_SIZE_BYTE_08;
+				break;
+			case JPEG_MARKER_APP0:
+			case JPEG_MARKER_APP13:
+			case JPEG_MARKER_COM:
+				eld->data_format = EL_DATA_FORMAT_JPEG;
+				eld->size = 0;
+				eld->state = EL_READ_SIZE_BYTE_08;
+				break;
+			case 0xff:
+			case JPEG_MARKER_SOI:
+				break;
+			default:
+				exif_log (eld->log,
+					EXIF_LOG_CODE_CORRUPT_DATA,
+					"ExifLoader", _("The data supplied "
+						"does not seem to contain "
+						"EXIF data."));
+				exif_loader_reset (eld);
+				return 0;
+			}
+		}
+
+	/*
+	 * If we reach this point, the buffer has not been big enough
+	 * to read all data we need. Fill it with new data.
+	 */
+	eld->b_len = 0;
+	return exif_loader_write (eld, buf, len);
+}
+
+ExifLoader *
+exif_loader_new (void)
+{
+	ExifMem *mem = exif_mem_new_default ();
+	ExifLoader *l = exif_loader_new_mem (mem);
+
+	exif_mem_unref (mem);
+
+	return l;
+}
+
+ExifLoader *
+exif_loader_new_mem (ExifMem *mem)
+{
+	ExifLoader *loader;
+
+	if (!mem) return NULL;
+	
+	loader = exif_mem_alloc (mem, sizeof (ExifLoader));
+	if (!loader) return NULL;
+	loader->ref_count = 1;
+
+	loader->mem = mem;
+	exif_mem_ref (mem);
+
+	return loader;
+}
+
+void
+exif_loader_ref (ExifLoader *loader)
+{
+	if (loader) loader->ref_count++;
+}
+
+static void
+exif_loader_free (ExifLoader *loader)
+{
+	ExifMem *mem;
+
+	if (!loader) return;
+
+	mem = loader->mem;
+	exif_loader_reset (loader);
+	exif_mem_free (mem, loader);
+	exif_mem_unref (mem);
+}
+	
+void
+exif_loader_unref (ExifLoader *loader)
+{
+	if (!loader) return;
+	if (!--loader->ref_count)
+		exif_loader_free (loader);
+}
+
+void
+exif_loader_reset (ExifLoader *loader)
+{
+	if (!loader) return;
+	exif_mem_free (loader->mem, loader->buf); loader->buf = NULL;
+	loader->size = 0;
+	loader->bytes_read = 0;
+	loader->state = 0;
+	loader->b_len = 0;
+	loader->data_format = EL_DATA_FORMAT_UNKNOWN;
+}
+
+ExifData *
+exif_loader_get_data (ExifLoader *loader)
+{
+	ExifData *ed;
+
+	if (!loader) return NULL;
+
+	ed = exif_data_new_mem (loader->mem);
+	exif_data_log (ed, loader->log);
+	exif_data_load_data (ed, loader->buf, loader->bytes_read);
+
+	return ed;
+}
+
+void
+exif_loader_log (ExifLoader *loader, ExifLog *log)
+{
+	if (!loader) return;
+	exif_log_unref (loader->log);
+	loader->log = log;
+	exif_log_ref (log);
+}