diff options
Diffstat (limited to 'raa.c')
| -rw-r--r-- | raa.c | 45 |
1 files changed, 45 insertions, 0 deletions
@@ -34,6 +34,51 @@ #include "nasmlib.h" #include "raa.h" +/* + * Routines to manage a dynamic random access array of int64_ts which + * may grow in size to be more than the largest single malloc'able + * chunk. + */ + +#define RAA_BLKSHIFT 15 /* 2**this many longs allocated at once */ +#define RAA_BLKSIZE (1 << RAA_BLKSHIFT) +#define RAA_LAYERSHIFT 15 /* 2**this many _pointers_ allocated */ +#define RAA_LAYERSIZE (1 << RAA_LAYERSHIFT) + +typedef struct RAA RAA; +typedef union RAA_UNION RAA_UNION; +typedef struct RAA_LEAF RAA_LEAF; +typedef struct RAA_BRANCH RAA_BRANCH; + +struct RAA { + /* + * Number of layers below this one to get to the real data. 0 + * means this structure is a leaf, holding RAA_BLKSIZE real + * data items; 1 and above mean it's a branch, holding + * RAA_LAYERSIZE pointers to the next level branch or leaf + * structures. + */ + int layers; + + /* + * Number of real data items spanned by one position in the + * `data' array at this level. This number is 0 trivially, for + * a leaf (level 0): for a level 1 branch it should be + * RAA_BLKSHIFT, and for a level 2 branch it's + * RAA_LAYERSHIFT+RAA_BLKSHIFT. + */ + int shift; + + union RAA_UNION { + struct RAA_LEAF { + int64_t data[RAA_BLKSIZE]; + } l; + struct RAA_BRANCH { + struct RAA *data[RAA_LAYERSIZE]; + } b; + } u; +}; + #define LEAFSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_LEAF)) #define BRANCHSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_BRANCH)) |