From 2ac260ae8694188410a408cd8c379a2fe45e4ee5 Mon Sep 17 00:00:00 2001 From: Martin Mares Date: Sun, 15 Feb 2009 00:21:09 +0100 Subject: [PATCH] More documentation of and . Still not complete. --- ucw/config.h | 34 ++++++------- ucw/doc/basics.txt | 26 +++++++++- ucw/lib.h | 117 ++++++++++++++++++++++++--------------------- 3 files changed, 105 insertions(+), 72 deletions(-) diff --git a/ucw/config.h b/ucw/config.h index f03572a5..a43e9ea5 100644 --- a/ucw/config.h +++ b/ucw/config.h @@ -1,7 +1,7 @@ /* * UCW Library -- Configuration-Dependent Definitions * - * (c) 1997--2007 Martin Mares + * (c) 1997--2009 Martin Mares * (c) 2006 Robert Spalek * * This software may be freely distributed and used according to the terms @@ -26,22 +26,22 @@ #include #include -typedef uint8_t byte; /* exactly 8 bits, unsigned */ -typedef uint8_t u8; /* exactly 8 bits, unsigned */ -typedef int8_t s8; /* exactly 8 bits, signed */ -typedef uint16_t u16; /* exactly 16 bits, unsigned */ -typedef int16_t s16; /* exactly 16 bits, signed */ -typedef uint32_t u32; /* exactly 32 bits, unsigned */ -typedef int32_t s32; /* exactly 32 bits, signed */ -typedef uint64_t u64; /* exactly 64 bits, unsigned */ -typedef int64_t s64; /* exactly 64 bits, signed */ - -typedef unsigned int uns; /* at least 32 bits */ -typedef u32 ucw_time_t; /* seconds since UNIX epoch */ -typedef s64 timestamp_t; /* milliseconds since UNIX epoch */ - -#ifdef CONFIG_LARGE_FILES /* File positions */ -typedef s64 ucw_off_t; +typedef uint8_t byte; /** Exactly 8 bits, unsigned **/ +typedef uint8_t u8; /** Exactly 8 bits, unsigned **/ +typedef int8_t s8; /** Exactly 8 bits, signed **/ +typedef uint16_t u16; /** Exactly 16 bits, unsigned **/ +typedef int16_t s16; /** Exactly 16 bits, signed **/ +typedef uint32_t u32; /** Exactly 32 bits, unsigned **/ +typedef int32_t s32; /** Exactly 32 bits, signed **/ +typedef uint64_t u64; /** Exactly 64 bits, unsigned **/ +typedef int64_t s64; /** Exactly 64 bits, signed **/ + +typedef unsigned int uns; /** A better pronounceable alias for `unsigned int` **/ +typedef u32 ucw_time_t; /** Seconds since UNIX epoch **/ +typedef s64 timestamp_t; /** Milliseconds since UNIX epoch **/ + +#ifdef CONFIG_LARGE_FILES +typedef s64 ucw_off_t; /** File position (either 32- or 64-bit, depending on `CONFIG_LARGE_FILES`). **/ #else typedef s32 ucw_off_t; #endif diff --git a/ucw/doc/basics.txt b/ucw/doc/basics.txt index 4400a7dc..29678438 100644 --- a/ucw/doc/basics.txt +++ b/ucw/doc/basics.txt @@ -1,9 +1,33 @@ LibUCW Basics ============= -*Currently, only the logging functions are documented.* +Every program using LibUCW should start with `#include ` which +brings in the most frequently used library functions, macros and types. +This should be done before you include any of the system headers, since +`lib.h` defines the feature macros of the system C library. + +Portability +----------- + +LibUCW is written in C99 with a couple of GNU extensions mixed in where needed. +It currently requires the GNU C compiler version 4.0 or newer, but most modules +should be very easy to adapt to a different C99 compiler. (A notable exception +is `stkstring.h`, which is heavily tied to GNU extensions.) + +The library has been developed on Linux with the GNU libc and it is know to run +on Darwin, too. The authors did not try using it on other systems, but most of +the code is written for a generic POSIX system, so porting to any UNIX-like system +should be a piece of cake. ucw/lib.h --------- +*Only partially documented.* !!ucw/lib.h + +ucw/config.h +------------ +This header contains the standard set of types used by LibUCW. It is automatically +included by `ucw/lib.h`. + +!!ucw/config.h diff --git a/ucw/lib.h b/ucw/lib.h index b7dcf429..a6228132 100644 --- a/ucw/lib.h +++ b/ucw/lib.h @@ -1,7 +1,7 @@ /* * The UCW Library -- Miscellaneous Functions * - * (c) 1997--2008 Martin Mares + * (c) 1997--2009 Martin Mares * (c) 2005 Tomas Valla * (c) 2006 Robert Spalek * (c) 2007 Pavel Charvat @@ -16,61 +16,70 @@ #include "ucw/config.h" #include -/* Macros for handling structurues, offsets and alignment */ +/*** === Macros for handling structures, offsets and alignment ***/ -#define CHECK_PTR_TYPE(x, type) ((x)-(type)(x) + (type)(x)) -#define PTR_TO(s, i) &((s*)0)->i -#define OFFSETOF(s, i) ((unsigned int) (uintptr_t) PTR_TO(s, i)) -#define SKIP_BACK(s, i, p) ((s *)((char *)p - OFFSETOF(s, i))) +#define CHECK_PTR_TYPE(x, type) ((x)-(type)(x) + (type)(x)) /** Check that a pointer @x is of type @type. Fail compilation if not. **/ +#define PTR_TO(s, i) &((s*)0)->i /** Return OFFSETOF() in form of a pointer. **/ +#define OFFSETOF(s, i) ((unsigned int) (uintptr_t) PTR_TO(s, i)) /** Offset of item @i from the start of structure @s **/ +#define SKIP_BACK(s, i, p) ((s *)((char *)p - OFFSETOF(s, i))) /** Given a pointer @p to item @i of structure @s, return a pointer to the start of the struct. **/ + +/** + * Align an integer @s to the nearest higher multiple of @a (which should be a power of two) + **/ #define ALIGN_TO(s, a) (((s)+a-1)&~(a-1)) + +/** + * Align a pointer @p to the nearest higher multiple of @s. + **/ #define ALIGN_PTR(p, s) ((uintptr_t)(p) % (s) ? (typeof(p))((uintptr_t)(p) + (s) - (uintptr_t)(p) % (s)) : (p)) + #define UNALIGNED_PART(ptr, type) (((uintptr_t) (ptr)) % sizeof(type)) -/* Some other macros */ +/*** === Other utility macros ***/ -#define MIN(a,b) (((a)<(b))?(a):(b)) -#define MAX(a,b) (((a)>(b))?(a):(b)) -#define CLAMP(x,min,max) ({ int _t=x; (_t < min) ? min : (_t > max) ? max : _t; }) -#define ABS(x) ((x) < 0 ? -(x) : (x)) -#define ARRAY_SIZE(a) (sizeof(a)/sizeof(*(a))) -#define STRINGIFY(x) #x -#define STRINGIFY_EXPANDED(x) STRINGIFY(x) -#define GLUE(x,y) x##y -#define GLUE_(x,y) x##_##y +#define MIN(a,b) (((a)<(b))?(a):(b)) /** Minimum of two numbers **/ +#define MAX(a,b) (((a)>(b))?(a):(b)) /** Maximum of two numbers **/ +#define CLAMP(x,min,max) ({ int _t=x; (_t < min) ? min : (_t > max) ? max : _t; }) /** Clip a number @x to interval [@min,@max] **/ +#define ABS(x) ((x) < 0 ? -(x) : (x)) /** Absolute value **/ +#define ARRAY_SIZE(a) (sizeof(a)/sizeof(*(a))) /** The number of elements of an array **/ +#define STRINGIFY(x) #x /** Convert macro parameter to a string **/ +#define STRINGIFY_EXPANDED(x) STRINGIFY(x) /** Convert an expanded macro parameter to a string **/ +#define GLUE(x,y) x##y /** Glue two tokens together **/ +#define GLUE_(x,y) x##_##y /** Glue two tokens together, separating them by an underscore **/ -#define COMPARE(x,y) do { if ((x)<(y)) return -1; if ((x)>(y)) return 1; } while(0) -#define REV_COMPARE(x,y) COMPARE(y,x) +#define COMPARE(x,y) do { if ((x)<(y)) return -1; if ((x)>(y)) return 1; } while(0) /** Numeric comparison function for qsort() **/ +#define REV_COMPARE(x,y) COMPARE(y,x) /** Reverse numeric comparison **/ #define COMPARE_LT(x,y) do { if ((x)<(y)) return 1; if ((x)>(y)) return 0; } while(0) #define COMPARE_GT(x,y) COMPARE_LT(y,x) -#define ROL(x, bits) (((x) << (bits)) | ((uns)(x) >> (sizeof(uns)*8 - (bits)))) /* Bitwise rotation of an uns to the left */ -#define ROR(x, bits) (((uns)(x) >> (bits)) | ((x) << (sizeof(uns)*8 - (bits)))) +#define ROL(x, bits) (((x) << (bits)) | ((uns)(x) >> (sizeof(uns)*8 - (bits)))) /** Bitwise rotation of an unsigned int to the left **/ +#define ROR(x, bits) (((uns)(x) >> (bits)) | ((x) << (sizeof(uns)*8 - (bits)))) /** Bitwise rotation of an unsigned int to the right **/ -/* GCC Extensions */ +/*** === Shortcuts for GCC Extensions ***/ #ifdef __GNUC__ #undef inline -#define NONRET __attribute__((noreturn)) -#define UNUSED __attribute__((unused)) -#define CONSTRUCTOR __attribute__((constructor)) -#define PACKED __attribute__((packed)) -#define CONST __attribute__((const)) -#define PURE __attribute__((pure)) -#define FORMAT_CHECK(x,y,z) __attribute__((format(x,y,z))) -#define likely(x) __builtin_expect((x),1) -#define unlikely(x) __builtin_expect((x),0) +#define NONRET __attribute__((noreturn)) /** Function does not return **/ +#define UNUSED __attribute__((unused)) /** Variable/parameter is knowingly unused **/ +#define CONSTRUCTOR __attribute__((constructor)) /** Call function upon start of program **/ +#define PACKED __attribute__((packed)) /** Structure should be packed **/ +#define CONST __attribute__((const)) /** Function depends only on arguments **/ +#define PURE __attribute__((pure)) /** Function depends only on arguments and global vars **/ +#define FORMAT_CHECK(x,y,z) __attribute__((format(x,y,z))) /** Checking of printf-like format strings **/ +#define likely(x) __builtin_expect((x),1) /** Use `if (likely(@x))` if @x is almost always true **/ +#define unlikely(x) __builtin_expect((x),0) /** Use `if (unlikely(@x))` to hint that @x is almost always false **/ #if __GNUC__ >= 4 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3 -#define ALWAYS_INLINE inline __attribute__((always_inline)) -#define NO_INLINE __attribute__((noinline)) +#define ALWAYS_INLINE inline __attribute__((always_inline)) /** Forcibly inline **/ +#define NO_INLINE __attribute__((noinline)) /** Forcibly uninline **/ #else #define ALWAYS_INLINE inline #endif #if __GNUC__ >= 4 -#define LIKE_MALLOC __attribute__((malloc)) -#define SENTINEL_CHECK __attribute__((sentinel)) +#define LIKE_MALLOC __attribute__((malloc)) /** Function returns a "new" pointer **/ +#define SENTINEL_CHECK __attribute__((sentinel)) /** The last argument must be NULL **/ #else #define LIKE_MALLOC #define SENTINEL_CHECK @@ -136,38 +145,38 @@ void assert_failed_noinfo(void) NONRET; #define DBG(x,y...) do { } while(0) #endif -/* Memory allocation */ - -#define xmalloc ucw_xmalloc -#define xrealloc ucw_xrealloc -#define xfree ucw_xfree +/*** === Memory allocation ***/ /* * Unfortunately, several libraries we might want to link to define * their own xmalloc and we don't want to interfere with them, hence * the renaming. */ -void *xmalloc(uns) LIKE_MALLOC; -void *xrealloc(void *, uns); -void xfree(void *); +#define xmalloc ucw_xmalloc +#define xrealloc ucw_xrealloc +#define xfree ucw_xfree + +void *xmalloc(uns) LIKE_MALLOC; /** Allocate memory and die() if there is none. **/ +void *xrealloc(void *, uns); /** Reallocate memory and die() if there is none. **/ +void xfree(void *); /** Free memory allocated by xmalloc() or xrealloc(). **/ -void *xmalloc_zero(uns) LIKE_MALLOC; -char *xstrdup(const char *) LIKE_MALLOC; +void *xmalloc_zero(uns) LIKE_MALLOC; /** Allocate memory and fill it by zeroes. **/ +char *xstrdup(const char *) LIKE_MALLOC; /** Make a xmalloc()'ed copy of a string. **/ -/* timer.c */ +/*** === Trivial timers (timer.c) ***/ -timestamp_t get_timestamp(void); +timestamp_t get_timestamp(void); /** Get current time as a millisecond timestamp. **/ -void init_timer(timestamp_t *timer); -uns get_timer(timestamp_t *timer); -uns switch_timer(timestamp_t *oldt, timestamp_t *newt); +void init_timer(timestamp_t *timer); /** Initialize a timer. **/ +uns get_timer(timestamp_t *timer); /** Get the number of milliseconds since last init/get of a timer. **/ +uns switch_timer(timestamp_t *oldt, timestamp_t *newt); /** Stop ticking of one timer and resume another. **/ -/* random.c */ +/*** === Random numbers (random.c) ***/ -uns random_u32(void); -uns random_max(uns max); -u64 random_u64(void); -u64 random_max_u64(u64 max); +uns random_u32(void); /** Return a pseudorandom 32-bit number. **/ +uns random_max(uns max); /** Return a pseudorandom 32-bit number in range [0,@max). **/ +u64 random_u64(void); /** Return a pseudorandom 64-bit number. **/ +u64 random_max_u64(u64 max); /** Return a pseudorandom 64-bit number in range [0,@max). **/ /* mmap.c */ -- 2.39.2