Add //third_party/sqlite to dirs_to_snapshot, remove net_sql.patch

third_party/sqlite/src/tool/logest.c

+/*
+** 2013-06-10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains a simple command-line utility for converting from
+** integers and LogEst values and back again and for doing simple
+** arithmetic operations (multiple and add) on LogEst values.
+**
+** Usage:
+**
+**      ./LogEst ARGS
+**
+** See the showHelp() routine for a description of valid arguments.
+** Examples:
+**
+** To convert 123 from LogEst to integer:
+** 
+**         ./LogEst ^123
+**
+** To convert 123456 from integer to LogEst:
+**
+**         ./LogEst 123456
+**
+*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <assert.h>
+#include <string.h>
+#include "sqlite3.h"
+
+typedef short int LogEst;  /* 10 times log2() */
+
+LogEst logEstMultiply(LogEst a, LogEst b){ return a+b; }
+LogEst logEstAdd(LogEst a, LogEst b){
+  static const unsigned char x[] = {
+     10, 10,                         /* 0,1 */
+      9, 9,                          /* 2,3 */
+      8, 8,                          /* 4,5 */
+      7, 7, 7,                       /* 6,7,8 */
+      6, 6, 6,                       /* 9,10,11 */
+      5, 5, 5,                       /* 12-14 */
+      4, 4, 4, 4,                    /* 15-18 */
+      3, 3, 3, 3, 3, 3,              /* 19-24 */
+      2, 2, 2, 2, 2, 2, 2,           /* 25-31 */
+  };
+  if( a<b ){ LogEst t = a; a = b; b = t; }
+  if( a>b+49 ) return a;
+  if( a>b+31 ) return a+1;
+  return a+x[a-b];
+}
+LogEst logEstFromInteger(sqlite3_uint64 x){
+  static LogEst a[] = { 0, 2, 3, 5, 6, 7, 8, 9 };
+  LogEst y = 40;
+  if( x<8 ){
+    if( x<2 ) return 0;
+    while( x<8 ){  y -= 10; x <<= 1; }
+  }else{
+    while( x>255 ){ y += 40; x >>= 4; }
+    while( x>15 ){  y += 10; x >>= 1; }
+  }
+  return a[x&7] + y - 10;
+}
+static sqlite3_uint64 logEstToInt(LogEst x){
+  sqlite3_uint64 n;
+  if( x<10 ) return 1;
+  n = x%10;
+  x /= 10;
+  if( n>=5 ) n -= 2;
+  else if( n>=1 ) n -= 1;
+  if( x>=3 ) return (n+8)<<(x-3);
+  return (n+8)>>(3-x);
+}
+static LogEst logEstFromDouble(double x){
+  sqlite3_uint64 a;
+  LogEst e;
+  assert( sizeof(x)==8 && sizeof(a)==8 );
+  if( x<=0.0 ) return -32768;
+  if( x<0.01 ) return -logEstFromDouble(1.0/x);
+  if( x<1.0 ) return logEstFromDouble(100.0*x) - 66;
+  if( x<1024.0 ) return logEstFromInteger((sqlite3_uint64)(1024.0*x)) - 100;
+  if( x<=2000000000.0 ) return logEstFromInteger((sqlite3_uint64)x);
+  memcpy(&a, &x, 8);
+  e = (a>>52) - 1022;
+  return e*10;
+}
+
+int isInteger(const char *z){
+  while( z[0]>='0' && z[0]<='9' ) z++;
+  return z[0]==0;
+}
+
+int isFloat(const char *z){
+  char c;
+  while( ((c=z[0])>='0' && c<='9') || c=='.' || c=='E' || c=='e'
+          || c=='+' || c=='-'  ) z++;
+  return z[0]==0;
+}
+
+static void showHelp(const char *zArgv0){
+  printf("Usage: %s ARGS...\n", zArgv0);
+  printf("Arguments:\n"
+    "  NUM    Convert NUM from integer to LogEst and push onto the stack\n"
+    " ^NUM    Interpret NUM as a LogEst and push onto stack\n"
+    "  x      Multiple the top two elements of the stack\n"
+    "  +      Add the top two elements of the stack\n"
+    "  dup    Dupliate the top element on the stack\n"
+    "  inv    Take the reciprocal of the top of stack.  N = 1/N.\n"
+    "  log    Find the LogEst of the number on top of stack\n"
+    "  nlogn  Compute NlogN where N is the top of stack\n"
+  );
+  exit(1);
+}
+
+int main(int argc, char **argv){
+  int i;
+  int n = 0;
+  LogEst a[100];
+  for(i=1; i<argc; i++){
+    const char *z = argv[i];
+    if( strcmp(z,"+")==0 ){
+      if( n>=2 ){
+        a[n-2] = logEstAdd(a[n-2],a[n-1]);
+        n--;
+      }
+    }else if( strcmp(z,"x")==0 ){
+      if( n>=2 ){
+        a[n-2] = logEstMultiply(a[n-2],a[n-1]);
+        n--;
+      }
+    }else if( strcmp(z,"dup")==0 ){
+      if( n>0 ){
+        a[n] = a[n-1];
+        n++;
+      }
+    }else if( strcmp(z,"log")==0 ){
+      if( n>0 ) a[n-1] = logEstFromInteger(a[n-1]) - 33;
+    }else if( strcmp(z,"nlogn")==0 ){
+      if( n>0 ) a[n-1] += logEstFromInteger(a[n-1]) - 33;
+    }else if( strcmp(z,"inv")==0 ){
+      if( n>0 ) a[n-1] = -a[n-1];
+    }else if( z[0]=='^' ){
+      a[n++] = atoi(z+1);
+    }else if( isInteger(z) ){
+      a[n++] = logEstFromInteger(atoi(z));
+    }else if( isFloat(z) && z[0]!='-' ){
+      a[n++] = logEstFromDouble(atof(z));
+    }else{
+      showHelp(argv[0]);
+    }
+  }
+  for(i=n-1; i>=0; i--){
+    if( a[i]<-40 ){
+      printf("%5d (%f)\n", a[i], 1.0/(double)logEstToInt(-a[i]));
+    }else if( a[i]<10 ){
+      printf("%5d (%f)\n", a[i], logEstToInt(a[i]+100)/1024.0);
+    }else{
+      sqlite3_uint64 x = logEstToInt(a[i]+100)*100/1024;
+      printf("%5d (%lld.%02lld)\n", a[i], x/100, x%100);
+    }
+  }
+  return 0;
+}