ref: f42e53655e9a2a1b516326f6522fba88db59a81c
dir: /sys/src/libdtracy/agg.c/
#include <u.h> #include <libc.h> #include <dtracy.h> int dtaunpackid(DTAgg *a) { a->type = a->id >> 28 & 15; a->keysize = a->id >> 13 & 0x7ff8; switch(a->type){ case AGGCNT: case AGGSUM: case AGGMIN: case AGGMAX: a->recsize = 8 + a->keysize + 8; return 0; case AGGAVG: a->recsize = 8 + a->keysize + 16; return 0; case AGGSTD: a->recsize = 8 + a->keysize + 32; return 0; default: return -1; } } static u64int hash(uchar *s, int n, int m) { u64int h; int i; h = 0xcbf29ce484222325ULL; for(i = 0; i < n; i++){ h ^= s[i]; h *= 0x100000001b3ULL; } for(; i < m; i++) h *= 0x100000001b3ULL; return h; } static int keyeq(uchar *a, uchar *b, int n, int m) { int i; for(i = 0; i < n; i++) if(a[i] != b[i]) return 0; for(; i < m; i++) if(a[i] != 0) return 0; return 1; } /* calculate v*v with 128 bits precision and add it to the 128-bit word at q */ static void addsquare(u64int *q, s64int v) { u32int v0; s32int v1; s64int s0, s1, s2; u64int r; v0 = v; v1 = v>>32; s0 = (s64int)v0 * (s64int)v0; s1 = (s64int)v0 * (s64int)v1; s2 = (s64int)v1 * (s64int)v1; r = s0 + (s1<<33); if(r < (u64int)s0) q[1]++; q[0] += r; if(q[0] < r) q[1]++; q[1] += s2 + (s1>>31); } static void updaterecord(int type, u64int *q, s64int val) { switch(type){ case AGGCNT: q[0] += 1; break; case AGGSUM: q[0] += val; break; case AGGAVG: q[0] += val; q[1]++; break; case AGGMIN: if(val < q[0]) q[0] = val; break; case AGGMAX: if(val > q[0]) q[0] = val; break; case AGGSTD: q[0] += val; q[1]++; addsquare(&q[2], val); break; } } static void createrecord(int type, u64int *q, s64int val) { switch(type){ case AGGCNT: q[0] = 1; break; case AGGSUM: case AGGMIN: case AGGMAX: q[0] = val; break; case AGGAVG: q[0] = val; q[1] = 1; break; case AGGSTD: q[0] = val; q[1] = 1; q[2] = 0; q[3] = 0; addsquare(&q[2], val); break; } } /* runs in probe context */ void dtarecord(DTChan *ch, int mach, DTAgg *a, uchar *key, int nkey, s64int val) { u64int h; u32int *p, *q; DTBuf *c; c = ch->aggwrbufs[mach]; h = hash(key, nkey, a->keysize); p = (u32int*)(c->data + DTABUCKETS + (h % DTANUMBUCKETS) * 4); while(*p != DTANIL){ assert((uint)*p < DTABUCKETS); q = (u32int*)(c->data + *p); if(q[1] == a->id && keyeq((uchar*)(q + 2), key, nkey, a->keysize) == 0){ updaterecord(a->type, (u64int*)(q + 2 + a->keysize / 4), val); return; } p = q; } if(c->wr + a->recsize > DTABUCKETS) return; *p = c->wr; q = (u32int*)(c->data + c->wr); q[0] = DTANIL; q[1] = a->id; if(nkey == a->keysize) memmove(&q[2], key, nkey); else if(nkey > a->keysize){ memmove(&q[2], key, nkey); memset((uchar*)q + 8 + nkey, 0, a->keysize - nkey); }else memmove(&q[2], key, a->keysize); createrecord(a->type, (u64int*)(q + 2 + a->keysize / 4), val); c->wr += a->recsize; }