1 files changed, 38 insertions, 0 deletions
diff --git a/libparsepcf_get_metrics_count.c b/libparsepcf_get_metrics_count.c
new file mode 100644
index 0000000..fab5544
--- /dev/null
+++ b/libparsepcf_get_metrics_count.c
@@ -0,0 +1,38 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+int
+libparsepcf_get_metrics_count(const char *file, size_t size, const struct libparsepcf_table *table, size_t *countp)
+{
+	size_t pos;
+	int msb = table->format & LIBPARSEPCF_BYTE;
+	int compressed = table->format & LIBPARSEPCF_COMPRESSED_METRICS;
+
+	if (table->size < (compressed ? 6 : 8))
+		goto ebfont;
+
+	pos = table->offset;
+
+	if (table->format != libparsepcf_parse_lsb_uint32__(&file[pos]))
+		goto ebfont;
+	pos += 4;
+
+	if (compressed) {
+		*countp = (size_t)PARSE_UINT16(&file[pos], msb);
+		pos += 2;
+		if (*countp > (size - pos) / 5)
+			goto ebfont;
+	} else {
+		*countp = (size_t)PARSE_UINT32(&file[pos], msb);
+		pos += 4;
+		if (*countp > (size - pos) / 12)
+			goto ebfont;
+	}
+
+	return 0;
+
+ebfont:
+	errno = EBFONT;
+	return -1;
+}