X-Git-Url: http://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/00d3a7a19623637e8010ad5afc6975cd33ea28f6..32081e3bb50124d451a660872f6dff57232e5172:/src/pack.c

diff --git a/src/pack.c b/src/pack.c
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+++ b/src/pack.c
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+/*
+ *  Portable binary serialisation of integral types.
+ *  Copyright (C) 2009 Nick Bowler
+ *
+ *  Copying and distribution of this file, with or without modification,
+ *  are permitted in any medium without royalty provided the copyright
+ *  notice and this notice are preserved.  This file is offered as-is,
+ *  without any warranty.
+ */
+
+#include "pack.h"
+
+/* Unsigned integer packing. */
+#define DEFPACK_BE(bits, type) void pack_ ## bits ## _be ( \
+	unsigned char *out, type v \
+) { \
+	unsigned i; \
+	for (i = 1; i <= bits/8; i++) { \
+		out[bits/8 - i] = v % 256; \
+		v /= 256; \
+	} \
+}
+
+#define DEFPACK_LE(bits, type) void pack_ ## bits ## _le ( \
+	unsigned char *out, type v \
+) { \
+	unsigned i; \
+	for (i = 0; i < bits/8; i++) { \
+		out[i] = v % 256; \
+		v /= 256; \
+	} \
+}
+
+DEFPACK_BE(16, unsigned short)
+DEFPACK_BE(32, unsigned long)
+#if PACK_HAVE_64BIT
+DEFPACK_BE(64, unsigned long long)
+#endif
+
+DEFPACK_LE(16, unsigned short)
+DEFPACK_LE(32, unsigned long)
+#if PACK_HAVE_64BIT
+DEFPACK_LE(64, unsigned long long)
+#endif
+
+#define DEFUNPACK_BE(bits, type) type unpack_ ## bits ## _be ( \
+	const unsigned char *in \
+) { \
+	type v = 0; \
+	unsigned i; \
+	for (i = 0; i < bits/8; i++) { \
+		v *= 256; \
+		v += in[i]; \
+	} \
+	return v; \
+}
+
+#define DEFUNPACK_LE(bits, type) type unpack_ ## bits ## _le ( \
+	const unsigned char *in \
+) { \
+	type v = 0; \
+	unsigned i; \
+	for (i = 1; i <= bits/8; i++) { \
+		v *= 256; \
+		v += in[bits/8 - i]; \
+	} \
+	return v; \
+}
+
+DEFUNPACK_BE(16, unsigned short)
+DEFUNPACK_BE(32, unsigned long)
+#if PACK_HAVE_64BIT
+DEFUNPACK_BE(64, unsigned long long)
+#endif
+
+DEFUNPACK_LE(16, unsigned short)
+DEFUNPACK_LE(32, unsigned long)
+#if PACK_HAVE_64BIT
+DEFUNPACK_LE(64, unsigned long long)
+#endif
+
+/*
+ * Two's complement signed integer packing.  This is unlikely to work on
+ * systems that don't themselves use two's complement.
+ */
+
+#define DEFUNPACK_SBE(bits, max, type) type unpack_s ## bits ## _be ( \
+	const unsigned char *in \
+) { \
+	type v = 0; \
+	unsigned i; \
+	int sign = (in[0] & 0x80) ? 1 : 0; \
+	for (i = 0; i < bits/8; i++) { \
+		v *= 256; \
+		v += in[i] & (i == 0 ? 0x7f : 0xff); \
+	} \
+	return sign*(-max-1) + v; \
+}
+
+#define DEFUNPACK_SLE(bits, max, type) type unpack_s ## bits ## _le ( \
+	const unsigned char *in \
+) { \
+	type v = 0; \
+	unsigned i; \
+	int sign = (in[bits/8 - 1] & 0x80) ? 1 : 0; \
+	for (i = 1; i <= bits/8; i++) { \
+		v *= 256; \
+		v += in[bits/8 - i] & (i == 1 ? 0x7f : 0xff); \
+	} \
+	return sign*(-max-1) + v; \
+}
+
+DEFUNPACK_SBE(16, 32767, short)
+DEFUNPACK_SBE(32, 2147483647l, long)
+#if PACK_HAVE_64BIT
+DEFUNPACK_SBE(64, 9223372036854775807ll, long long)
+#endif
+
+DEFUNPACK_SLE(16, 32767, short)
+DEFUNPACK_SLE(32, 2147483647l, long)
+#if PACK_HAVE_64BIT
+DEFUNPACK_SLE(64, 9223372036854775807ll, long long)
+#endif