ucw/ff-binary.h

   1 /*
   2  *      UCW Library -- Fast Buffered I/O on Binary Values
   3  *
   4  *      (c) 1997--2007 Martin Mares <mj@ucw.cz>
   5  *      (c) 2004 Robert Spalek <robert@ucw.cz>
   6  *
   7  *      This software may be freely distributed and used according to the terms
   8  *      of the GNU Lesser General Public License.
   9  */
  10
  11 #ifndef _UCW_FF_BINARY_H
  12 #define _UCW_FF_BINARY_H
  13
  14 #include <ucw/fastbuf.h>
  15 #include <ucw/unaligned.h>
  16
  17 #ifdef CPU_BIG_ENDIAN
  18 #define FF_ENDIAN be
  19 #else
  20 #define FF_ENDIAN le
  21 #endif
  22
  23 /***
  24  *
  25  * We define several functions to read or write binary integer values.
  26  *
  27  * The name patterns for such routines are:
  28  *
  29  * - `TYPE bget \#\# NAME \#\# ENDIAN(struct fastbuf *f);`
  30  * - `void bput \#\# NAME \#\# ENDIAN(struct fastbuf *f, TYPE value);`
  31  *
  32  * where `NAME` together with `TYPE` can be:
  33  *
  34  * - `w` for 16-bit unsigned integers stored in sequences of 2 bytes, the `TYPE` is int
  35  * - `l` for 32-bit unsigned integers stored in sequences of 4 bytes, the `TYPE` is uns
  36  * - `5` for 40-bit unsigned integers stored in sequences of 5 bytes, the `TYPE` is u64
  37  * - `q` for 64-bit unsigned integers stored in sequences of 8 bytes, the `TYPE` is u64
  38  *
  39  * and supported `ENDIAN` suffixes are:
  40  *
  41  * - empty for the default order of bytes (defined by CPU)
  42  * - `_le` for little-endian
  43  * - `_be` for big-endian
  44  *
  45  * If we fail to read enough bytes because of EOF, the reading function returns `(TYPE)-1`.
  46  *
  47  ***/
  48
  49 #define GET_FUNC(type, name, bits, endian)                      \
  50   type bget##name##_##endian##_slow(struct fastbuf *f);         \
  51   static inline type bget##name##_##endian(struct fastbuf *f)   \
  52   {                                                             \
  53     if (bavailr(f) >= bits/8)                                   \
  54       {                                                         \
  55         type w = get_u##bits##_##endian(f->bptr);               \
  56         f->bptr += bits/8;                                      \
  57         return w;                                               \
  58       }                                                         \
  59     else                                                        \
  60       return bget##name##_##endian##_slow(f);                   \
  61   }
  62
  63 #define PUT_FUNC(type, name, bits, endian)                      \
  64   void bput##name##_##endian##_slow(struct fastbuf *f, type x); \
  65   static inline void bput##name##_##endian(struct fastbuf *f, type x)   \
  66   {                                                             \
  67     if (bavailw(f) >= bits/8)                                   \
  68       {                                                         \
  69         put_u##bits##_##endian(f->bptr, x);                     \
  70         f->bptr += bits/8;                                      \
  71       }                                                         \
  72     else                                                        \
  73       return bput##name##_##endian##_slow(f, x);                \
  74   }
  75
  76 #define FF_ALL_X(type, name, bits, defendian)                   \
  77   GET_FUNC(type, name, bits, be)                                \
  78   GET_FUNC(type, name, bits, le)                                \
  79   PUT_FUNC(type, name, bits, be)                                \
  80   PUT_FUNC(type, name, bits, le)                                \
  81   static inline type bget##name(struct fastbuf *f) { return bget##name##_##defendian(f); }              \
  82   static inline void bput##name(struct fastbuf *f, type x) { bput##name##_##defendian(f, x); }
  83
  84 #define FF_ALL(type, name, bits, defendian) FF_ALL_X(type, name, bits, defendian)
  85
  86 FF_ALL(int, w, 16, FF_ENDIAN)
  87 FF_ALL(uns, l, 32, FF_ENDIAN)
  88 FF_ALL(u64, q, 64, FF_ENDIAN)
  89 FF_ALL(u64, 5, 40, FF_ENDIAN)
  90
  91 #undef GET_FUNC
  92 #undef PUT_FUNC
  93 #undef FF_ENDIAN
  94 #undef FF_ALL_X
  95 #undef FF_ALL
  96
  97 /* I/O on uintptr_t (only native endianity) */
  98
  99 #ifdef CPU_64BIT_POINTERS
 100 #define bputa(x,p) bputq(x,p)
 101 #define bgeta(x) bgetq(x)
 102 #else
 103 #define bputa(x,p) bputl(x,p)
 104 #define bgeta(x) bgetl(x)
 105 #endif
 106
 107 #endif