Initial community commit

Src/nsmkv/read.cpp

@@ -0,0 +1,154 @@
+#include "read.h"
+#include "vint.h"
+#include "ebml_float.h"
+#include "ebml_unsigned.h"
+#include "ebml_signed.h"
+#include <limits.h>
+#ifdef WA_VALIDATE
+extern uint64_t max_id_length;
+extern uint64_t max_size_length;
+#endif
+
+// returns bytes read.  0 means EOF
+uint64_t read_vint(nsmkv::MKVReader *reader, uint64_t *val)
+{
+	uint8_t data[9] = {0};
+	size_t bytes_read = 0;
+	reader->Read(data, 1, &bytes_read);
+
+	if (bytes_read != 1)
+		return 0;
+	uint8_t length = vint_get_number_bytes(data[0]);
+	reader->Read(data+1, length, &bytes_read);
+	if (bytes_read != length)
+		return 0;
+
+	*val = vint_read_ptr(data);
+	return bytes_read+1;
+}
+
+
+// returns bytes read.  0 means EOF
+uint64_t read_ebml_node(nsmkv::MKVReader *reader, ebml_node *node)
+{
+	uint64_t bytes_read = read_vint(reader, &node->id);
+	if (!bytes_read)
+		return 0;
+
+	bytes_read += read_vint(reader, &node->size);
+
+	return bytes_read;
+}
+
+uint64_t read_utf8(nsmkv::MKVReader *reader, uint64_t size, char **utf8)
+{
+	if (utf8)
+	{
+		if (size == SIZE_MAX) // prevent integer overflow
+			return 0;
+
+		char *&val = *utf8;
+		val = (char *)calloc((size_t)size + 1, sizeof(char));
+		if (val)
+		{
+			val[size]=0;
+			size_t bytes_read;
+			reader->Read(val, (size_t)size, &bytes_read);
+			if (bytes_read != (size_t)size)
+			{
+				free(val);
+				return 0;
+			}
+
+			return size;
+		}
+		return 0; // actually, out of memory and not EOF, but still we should abort ASAP
+	}
+	else
+	{
+		reader->Skip(size);
+		return size;
+	}
+}
+
+#if 0
+int fseek64(nsmkv::MKVReader *reader, int64_t pos, int whence)
+{
+	switch(whence)
+	{
+	case SEEK_SET:
+		return fsetpos(f, &pos);
+	case SEEK_CUR:
+		{
+			fpos_t curpos=0;
+			int ret = fgetpos(f, &curpos);
+			if (ret != 0)
+				return ret;
+			pos+=curpos;
+			return fsetpos(f, &pos);
+		}
+	case SEEK_END:
+		{
+			return _fseeki64(f, pos, SEEK_END);
+		}
+	}
+	return 1;
+}
+
+int64_t ftell64(nsmkv::MKVReader *reader)
+{
+	fpos_t pos;
+	if (fgetpos(f, &pos) == 0)
+		return pos;
+	else
+		return -1L;
+}
+#endif
+uint64_t read_unsigned(nsmkv::MKVReader *reader, uint64_t size, uint64_t *val)
+{
+	uint8_t data[8] = {0};
+	if (size == 0 || size > 8)
+		return 0;
+
+	size_t bytes_read = 0;
+	reader->Read(data, (size_t)size, &bytes_read);
+	if (bytes_read != size)
+	{
+		return 0;
+	}
+	*val = unsigned_read_ptr_len(size, data);
+	return size;
+}
+
+uint64_t read_float(nsmkv::MKVReader *reader, uint64_t size, double *val)
+{
+	uint8_t data[10] = {0};
+	if (size == 0 || size > 10)
+		return 0;
+
+	size_t bytes_read = 0;
+	reader->Read(data, (size_t)size, &bytes_read);
+	if (bytes_read != size)
+	{
+		return 0;
+	}
+	*val = float_read_ptr_len(size, data);
+	return size;
+}
+
+uint64_t read_signed(nsmkv::MKVReader *reader, uint64_t size, int64_t *val)
+{
+	uint8_t data[8] = {0};
+	if (size == 0 || size > 8)
+		return 0;
+
+	size_t bytes_read = 0;
+	reader->Read(data, (size_t)size, &bytes_read);
+	if (bytes_read != size)
+	{
+		return 0;
+	}
+	*val = signed_read_ptr_len(size, data);
+	return size;
+}
+