From: Rusty Russell <rusty@rustcorp.com.au>
Date: Sat, 18 Jul 2009 08:38:05 +0000 (+0930)
Subject: Short types
X-Git-Url: http://git.ozlabs.org/?p=ccan;a=commitdiff_plain;h=3d937beb970d5b52bdaaf41d75e7a0b8eb89d472

Short types
---

diff --git a/ccan/short_types/_info b/ccan/short_types/_info
new file mode 100644
index 00000000..bc69b1b9
--- /dev/null
+++ b/ccan/short_types/_info
@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * short_types - shorter names for standard integer types
+ *
+ * "C is a Spartan language, and so should your naming be."
+ *	-- Linus Torvalds
+ *
+ * The short_types header provides for convenient abbreviations for the
+ * posixly-damned uint32_t types.  It also provides be32/le32 for explicitly
+ * annotating types of specific endian.
+ *
+ * Include this header, if only to stop people using these identifiers
+ * for other things!
+ *
+ * Example:
+ *	#include <stdint.h>
+ *	#include <string.h>
+ *	#include <stdio.h>
+ *	#include <ccan/short_types/short_types.h>
+ *	
+ *	// Print nonsensical numerical comparison of POSIX vs. short_types. 
+ *	#define stringify_1(x)	#x
+ *	#define stringify(x)	stringify_1(x)
+ *	
+ *	static void evaluate(size_t size, const char *posix, const char *sht,
+ *			     unsigned int *posix_total, unsigned int *sht_total,
+ *			     unsigned int *size_total)
+ *	{
+ *		printf("\t%ssigned %s: POSIX %i%%, short %i%%\n",
+ *		       sht[0] == 'u' ? "un" : "",
+ *		       sht+1,
+ *		       strlen(posix)*100 / size,
+ *		       strlen(sht)*100 / size);
+ *		*posix_total += strlen(posix);
+ *		*sht_total += strlen(sht);
+ *		*size_total += size;
+ *	}
+ *
+ *	#define EVALUATE(psx, short, pt, st, t)				\
+ *		evaluate(sizeof(psx), stringify(psx), stringify(sht), pt, st, t)
+ *
+ *	int main(void)
+ *	{
+ *		unsigned int posix_total = 0, sht_total = 0, size_total = 0;
+ *
+ *		printf("Comparing size of type vs size of name:\n");
+ *
+ *		EVALUATE(uint8_t, u8, &posix_total, &sht_total, &size_total);
+ *		EVALUATE(int8_t, s8, &posix_total, &sht_total, &size_total);
+ *		EVALUATE(uint16_t, u16, &posix_total, &sht_total, &size_total);
+ *		EVALUATE(int16_t, s16, &posix_total, &sht_total, &size_total);
+ *		EVALUATE(uint32_t, u32, &posix_total, &sht_total, &size_total);
+ *		EVALUATE(int32_t, s32, &posix_total, &sht_total, &size_total);
+ *		EVALUATE(uint64_t, u64, &posix_total, &sht_total, &size_total);
+ *		EVALUATE(int64_t, s64, &posix_total, &sht_total, &size_total);
+ *
+ *		printf("Conclusion:\n"
+ *		       "\tPOSIX is %u%% LESS efficient than binary.\n"
+ *		       "\tshort_types.h is %u%% MORE efficient than binary.\n",
+ *		       (posix_total - size_total) * 100 / size_total,
+ *		       (size_total - sht_total) * 100 / size_total);
+ *		return 0;
+ *	}
+ *
+ * Licence: LGPL (2 or any later version)
+ */
+int main(int argc, char *argv[])
+{
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0) {
+		return 0;
+	}
+
+	return 1;
+}
diff --git a/ccan/short_types/short_types.h b/ccan/short_types/short_types.h
new file mode 100644
index 00000000..e34efe0e
--- /dev/null
+++ b/ccan/short_types/short_types.h
@@ -0,0 +1,31 @@
+#ifndef CCAN_SHORT_TYPES_H
+#define CCAN_SHORT_TYPES_H
+#include <stdint.h>
+
+/**
+ * u64/s64/u32/s32/u16/s16/u8/s8 - short names for explicitly-sized types.
+ */
+typedef uint64_t u64;
+typedef int64_t s64;
+typedef uint32_t u32;
+typedef int32_t s32;
+typedef uint16_t u16;
+typedef int16_t s16;
+typedef uint8_t u8;
+typedef int8_t s8;
+
+/**
+ * be64/be32/be16 - 64/32/16 bit big-endian representation.
+ */
+typedef uint64_t be64;
+typedef uint32_t be32;
+typedef uint16_t be16;
+
+/**
+ * le64/le32/le16 - 64/32/16 bit little-endian representation.
+ */
+typedef uint64_t le64;
+typedef uint32_t le32;
+typedef uint16_t le16;
+
+#endif /* CCAN_SHORT_TYPES_H */
diff --git a/ccan/short_types/test/run.c b/ccan/short_types/test/run.c
new file mode 100644
index 00000000..a78d56ce
--- /dev/null
+++ b/ccan/short_types/test/run.c
@@ -0,0 +1,38 @@
+#include "short_types/short_types.h"
+#include "tap/tap.h"
+#include <stdlib.h>
+#include <err.h>
+
+int main(int argc, char *argv[])
+{
+	plan_tests(22);
+
+	ok1(sizeof(u64) == 8);
+	ok1(sizeof(s64) == 8);
+	ok1(sizeof(u32) == 4);
+	ok1(sizeof(s32) == 4);
+	ok1(sizeof(u16) == 2);
+	ok1(sizeof(s16) == 2);
+	ok1(sizeof(u8) == 1);
+	ok1(sizeof(s8) == 1);
+
+	ok1(sizeof(be64) == 8);
+	ok1(sizeof(be32) == 4);
+	ok1(sizeof(be16) == 2);
+
+	ok1(sizeof(le64) == 8);
+	ok1(sizeof(le32) == 4);
+	ok1(sizeof(le16) == 2);
+
+	/* Signedness tests. */
+	ok1((u64)-1 > 0);
+	ok1((u32)-1 > 0);
+	ok1((u16)-1 > 0);
+	ok1((u8)-1 > 0);
+	ok1((s64)-1 < 0);
+	ok1((s32)-1 < 0);
+	ok1((s16)-1 < 0);
+	ok1((s8)-1 < 0);
+
+	return exit_status();
+}