【Go 语言社区】Golang源码解读之map

struct Hmap
{
        uintgo  count;        // # live cells == size of map.  Must be first (used by len() builtin)
        uint32  flags;
        uint32  hash0;        // hash seed
        uint8   B;            // log_2 of # of buckets (can hold up to LOAD * 2^B items)
        uint8   keysize;      // key size in bytes
        uint8   valuesize;    // value size in bytes
        uint16  bucketsize;   // bucket size in bytes
        byte    *buckets;     // array of 2^B Buckets. may be nil if count==0.
        byte    *oldbuckets;  // previous bucket array of half the size, non-nil only when growing
        uintptr nevacuate;    // progress counter for evacuation (buckets less than this have been evacuated)
};
typedef struct Bucket Bucket;
struct Bucket
{
        uint8  tophash[BUCKETSIZE]; // top 8 bits of hash of each entry (0 = empty)
        Bucket *overflow;           // overflow bucket, if any
        byte   data[1];             // BUCKETSIZE keys followed by BUCKETSIZE values
};