From 310f7fe7a60467569f9d62d97847bc36dd5eb4ca Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Fri, 5 Aug 2016 14:36:27 -0400 Subject: VPP-223 Document vppinfra/bitmap.h Change-Id: I259a5b716bd8a7abdb0e6bf778432f034338ffdc Signed-off-by: Dave Barach --- vppinfra/vppinfra/bitmap.h | 248 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 210 insertions(+), 38 deletions(-) (limited to 'vppinfra') diff --git a/vppinfra/vppinfra/bitmap.h b/vppinfra/vppinfra/bitmap.h index 17b72ac6c1f..80f1b4f191b 100644 --- a/vppinfra/vppinfra/bitmap.h +++ b/vppinfra/vppinfra/bitmap.h @@ -38,7 +38,9 @@ #ifndef included_clib_bitmap_h #define included_clib_bitmap_h -/* Bitmaps built as vectors of machine words. */ +/** \file + Bitmaps built as vectors of machine words +*/ #include #include @@ -47,7 +49,10 @@ typedef uword clib_bitmap_t; -/* Returns 1 if the entire bitmap is zero, 0 otherwise */ +/** predicate function; is an entire bitmap empty? + @param ai - pointer to a bitmap + @returns 1 if the entire bitmap is zero, 0 otherwise +*/ always_inline uword clib_bitmap_is_zero (uword * ai) { @@ -58,7 +63,11 @@ clib_bitmap_is_zero (uword * ai) return 1; } -/* Returns 1 if two bitmaps are equal, 0 otherwise */ +/** predicate function; are two bitmaps equal? + @param a - pointer to a bitmap + @param b - pointer to a bitmap + @returns 1 if the bitmaps are equal, 0 otherwise +*/ always_inline uword clib_bitmap_is_equal (uword * a, uword * b) { @@ -71,19 +80,32 @@ clib_bitmap_is_equal (uword * a, uword * b) return 1; } -/* Duplicate a bitmap */ +/** Duplicate a bitmap + @param ai - pointer to a bitmap + @returns a duplicate of the bitmap +*/ #define clib_bitmap_dup(v) vec_dup(v) -/* Free a bitmap */ +/** Free a bitmap + @param v - pointer to the bitmap to free +*/ #define clib_bitmap_free(v) vec_free(v) -/* Returns the number of bytes in a bitmap */ +/** Number of bytes in a bitmap + @param v - pointer to the bitmap +*/ #define clib_bitmap_bytes(v) vec_bytes(v) -/* Clear a bitmap */ +/** Clear a bitmap + @param v - pointer to the bitmap to clear +*/ #define clib_bitmap_zero(v) vec_zero(v) -/* Allocate bitmap with given number of bits. */ +/** Allocate a bitmap with the supplied number of bits + @param [out] v - the resulting bitmap + @param n_bits - the required number of bits +*/ + #define clib_bitmap_alloc(v,n_bits) \ v = vec_new (uword, ((n_bits) + BITS (uword) - 1) / BITS (uword)) @@ -108,8 +130,13 @@ _clib_bitmap_remove_trailing_zeros (uword * a) return a; } -/* Sets the ith bit of a bitmap to new_value. Returns old value. - No sanity checking. Be careful. */ +/** Sets the ith bit of a bitmap to new_value. + No sanity checking. Be careful. + @param a - pointer to the bitmap + @param i - the bit position to interrogate + @param new_value - new value for the bit + @returns the old value of the bit +*/ always_inline uword clib_bitmap_set_no_check (uword * a, uword i, uword new_value) { @@ -129,7 +156,13 @@ clib_bitmap_set_no_check (uword * a, uword i, uword new_value) return old_value; } -/* Set bit I to value (either non-zero or zero). */ +/** Sets the ith bit of a bitmap to new_value + Removes trailing zeros from the bitmap + @param a - pointer to the bitmap + @param i - the bit position to interrogate + @param new_value - new value for the bit + @returns the old value of the bit +*/ always_inline uword * clib_bitmap_set (uword * ai, uword i, uword value) { @@ -155,7 +188,11 @@ clib_bitmap_set (uword * ai, uword i, uword value) return ai; } -/* Fetch bit I. */ +/** Gets the ith bit value from a bitmap + @param ai - pointer to the bitmap + @param i - the bit position to interrogate + @returns the indicated bit value +*/ always_inline uword clib_bitmap_get (uword * ai, uword i) { @@ -164,9 +201,12 @@ clib_bitmap_get (uword * ai, uword i) return i0 < vec_len (ai) && 0 != ((ai[i0] >> i1) & 1); } -/* Fetch bit I. - - No sanity checking. Be careful. +/** Gets the ith bit value from a bitmap + Does not sanity-check the bit position. Be careful. + @param ai - pointer to the bitmap + @param i - the bit position to interrogate + @returns the indicated bit value, or garbage if the bit position is + out of range. */ always_inline uword clib_bitmap_get_no_check (uword * ai, uword i) @@ -176,10 +216,6 @@ clib_bitmap_get_no_check (uword * ai, uword i) return 0 != ((ai[i0] >> i1) & 1); } -/* I through I + N_BITS. - - No sanity checking. Be careful. -*/ always_inline uword clib_bitmap_get_multiple_no_check (uword * ai, uword i, uword n_bits) { @@ -189,7 +225,12 @@ clib_bitmap_get_multiple_no_check (uword * ai, uword i, uword n_bits) return 0 != ((ai[i0] >> i1) & pow2_mask (n_bits)); } -/* Fetch bits I through I + N_BITS. */ +/** Gets the ith through ith + n_bits bit values from a bitmap + @param bitmap - pointer to the bitmap + @param i - the first bit position to retrieve + @param n_bits - the number of bit positions to retrieve + @returns the indicated range of bits +*/ always_inline uword clib_bitmap_get_multiple (uword * bitmap, uword i, uword n_bits) { @@ -221,9 +262,14 @@ clib_bitmap_get_multiple (uword * bitmap, uword i, uword n_bits) return result; } -/* Set bits I through I + N_BITS to given value. +/** sets the ith through ith + n_bits bits in a bitmap + @param bitmap - pointer to the bitmap + @param i - the first bit position to retrieve + @param value - the values to set + @param n_bits - the number of bit positions to set + @returns a pointer to the updated bitmap, which may expand and move +*/ - New bitmap will be returned. */ always_inline uword * clib_bitmap_set_multiple (uword * bitmap, uword i, uword value, uword n_bits) { @@ -266,9 +312,8 @@ clib_bitmap_set_multiple (uword * bitmap, uword i, uword value, uword n_bits) return bitmap; } -/* For a multi-word region set all bits to given value. */ always_inline uword * -clib_bitmap_set_region (uword * bitmap, uword i, uword value, uword n_bits) +clfib_bitmap_set_region (uword * bitmap, uword i, uword value, uword n_bits) { uword a0, a1, b0; uword i_end, mask; @@ -306,7 +351,12 @@ clib_bitmap_set_region (uword * bitmap, uword i, uword value, uword n_bits) return bitmap; } -/* Iterate through set bits. */ +/** Macro to iterate across set bits in a bitmap + + @param i - the current set bit + @param ai - the bitmap + @param body - the expression to evaluate for each set bit +*/ #define clib_bitmap_foreach(i,ai,body) \ do { \ uword __bitmap_i, __bitmap_ai, __bitmap_len, __bitmap_first_set; \ @@ -325,9 +375,11 @@ do { \ } \ } while (0) -/* Return lowest numbered set bit in bitmap. - Return infinity (~0) if bitmap is zero. */ +/** Return the lowest numbered set bit in a bitmap + @param ai - pointer to the bitmap + @returns lowest numbered set bit, or ~0 if the entire bitmap is zero +*/ always_inline uword clib_bitmap_first_set (uword * ai) { uword i; @@ -340,9 +392,10 @@ always_inline uword clib_bitmap_first_set (uword * ai) return ~0; } -/* Return highest numbered set bit in bitmap. - - Return infinity (~0) if bitmap is zero. */ +/** Return the higest numbered set bit in a bitmap + @param ai - pointer to the bitmap + @returns lowest numbered set bit, or ~0 if the entire bitmap is zero +*/ always_inline uword clib_bitmap_last_set (uword * ai) { uword i; @@ -360,7 +413,10 @@ always_inline uword clib_bitmap_last_set (uword * ai) return ~0; } -/* Return lowest numbered clear bit in bitmap. */ +/** Return the lowest numbered clear bit in a bitmap + @param ai - pointer to the bitmap + @returns lowest numbered clear bit +*/ always_inline uword clib_bitmap_first_clear (uword * ai) { @@ -374,7 +430,10 @@ clib_bitmap_first_clear (uword * ai) return i * BITS (ai[0]); } -/* Count number of set bits in bitmap. */ +/** Return the number of set bits in a bitmap + @param ai - pointer to the bitmap + @returns the number of set bits in the bitmap +*/ always_inline uword clib_bitmap_count_set_bits (uword * ai) { @@ -385,6 +444,50 @@ clib_bitmap_count_set_bits (uword * ai) return n_set; } +/** Logical operator across two bitmaps + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns ai = ai and bi. ai is modified, bi is not modified +*/ +always_inline uword * +clib_bitmap_and (uword * ai, uword * bi); + +/** Logical operator across two bitmaps + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns ai = ai & ~bi. ai is modified, bi is not modified +*/ +always_inline uword * +clib_bitmap_andnot (uword * ai, uword * bi); + +/** Logical operator across two bitmaps + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns ai = ai & ~bi. ai is modified, bi is not modified +*/ +always_inline uword * +clib_bitmap_or (uword * ai, uword * bi); +/** Logical operator across two bitmaps + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns ai = ai or bi. ai is modified, bi is not modified +*/ +always_inline uword * +clib_bitmap_or (uword * ai, uword * bi); + +/** Logical operator across two bitmaps + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns ai = ai xor bi. ai is modified, bi is not modified +*/ +always_inline uword * +clib_bitmap_xor (uword * ai, uword * bi); + /* ALU function definition macro for functions taking two bitmaps. */ #define _(name, body, check_zero) \ always_inline uword * \ @@ -417,8 +520,42 @@ _ (or, a = a | b, 0) _ (xor, a = a ^ b, 1) #undef _ -/* Define functions which duplicate first argument. - (Normal functions over-write first argument.) */ +/** Logical operator across two bitmaps which duplicates the first bitmap + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns aiDup = ai and bi. Neither ai nor bi are modified +*/ +always_inline uword * +clib_bitmap_dup_and (uword * ai, uword * bi); + +/** Logical operator across two bitmaps which duplicates the first bitmap + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns aiDup = ai & ~bi. Neither ai nor bi are modified +*/ +always_inline uword * +clib_bitmap_dup_andnot (uword * ai, uword * bi); + +/** Logical operator across two bitmaps which duplicates the first bitmap + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns aiDup = ai or bi. Neither ai nor bi are modified +*/ +always_inline uword * +clib_bitmap_dup_or (uword * ai, uword * bi); + +/** Logical operator across two bitmaps which duplicates the first bitmap + + @param ai - pointer to the destination bitmap + @param bi - pointer to the source bitmap + @returns aiDup = ai xor bi. Neither ai nor bi are modified +*/ +always_inline uword * +clib_bitmap_dup_xor (uword * ai, uword * bi); + #define _(name) \ always_inline uword * \ clib_bitmap_dup_##name (uword * ai, uword * bi) \ @@ -457,7 +594,12 @@ _ (xori, a = a ^ b, 1) #undef _ -/* Returns random bitmap of given length. */ +/** Return a random bitmap of the requested length + @param ai - pointer to the destination bitmap + @param n_bits - number of bits to allocate + @param [in/out] seed - pointer to the random number seed + @returns a reasonably random bitmap based. See random.h. +*/ always_inline uword * clib_bitmap_random (uword * ai, uword n_bits, u32 * seed) { @@ -487,7 +629,12 @@ clib_bitmap_random (uword * ai, uword n_bits, u32 * seed) return ai; } -/* Returns next set bit starting at bit i (~0 if not found). */ +/** Return the next set bit in a bitmap starting at bit i + @param ai - pointer to the bitmap + @param i - first bit position to test + @returns first set bit position at or after i, + ~0 if no further set bits are found +*/ always_inline uword clib_bitmap_next_set (uword * ai, uword i) { @@ -512,7 +659,11 @@ clib_bitmap_next_set (uword * ai, uword i) return ~0; } -/* Returns next clear bit at position >= i */ +/** Return the next clear bit in a bitmap starting at bit i + @param ai - pointer to the bitmap + @param i - first bit position to test + @returns first clear bit position at or after i +*/ always_inline uword clib_bitmap_next_clear (uword * ai, uword i) { @@ -536,7 +687,17 @@ clib_bitmap_next_clear (uword * ai, uword i) return i; } -/* unformat list of bits into bitmap (eg "0-3,5-7,11" ) */ +/** unformat a list of bit ranges into a bitmap (eg "0-3,5-7,11" ) + + uword * bitmap; + rv = unformat ("%U", unformat_bitmap_list, &bitmap); + + Standard unformat_function_t arguments + + @param input - pointer an unformat_input_t + @param va - varargs list comprising a single uword ** + @returns 1 on success, 0 on failure +*/ static inline uword unformat_bitmap_list(unformat_input_t * input, va_list * va) { @@ -577,6 +738,17 @@ error: return 0; } +/** Format a bitmap as a string of hex bytes + + uword * bitmap; + s = format ("%U", format_bitmap_hex, bitmap); + + Standard format_function_t arguments + + @param s - string under construction + @param args - varargs list comprising a single uword * + @returns string under construction +*/ static inline u8 * format_bitmap_hex(u8 * s, va_list * args) { -- cgit 1.2.3-korg