mod_query/history.c

   1 /*
   2  * ion/mod_query/history.h
   3  *
   4  * Copyright (c) Tuomo Valkonen 1999-2009.
   5  *
   6  * See the included file LICENSE for details.
   7  */
   8
   9 #include <string.h>
  10
  11 #include <ioncore/common.h>
  12 #include <libextl/extl.h>
  13
  14 #include "history.h"
  15
  16
  17 #define HISTORY_SIZE 1024
  18
  19
  20 static int hist_head=HISTORY_SIZE;
  21 static int hist_count=0;
  22 static char *hist[HISTORY_SIZE];
  23
  24
  25 int get_index(int i)
  26 {
  27     if(i<0 || i>=hist_count)
  28         return -1;
  29     return (hist_head+i)%HISTORY_SIZE;
  30 }
  31
  32
  33 /*EXTL_DOC
  34  * Push an entry into line editor history.
  35  */
  36 EXTL_EXPORT
  37 bool mod_query_history_push(const char *str)
  38 {
  39     char *s=scopy(str);
  40
  41     if(s==NULL)
  42         return FALSE;
  43
  44     mod_query_history_push_(s);
  45
  46     return TRUE;
  47 }
  48
  49
  50 void mod_query_history_push_(char *str)
  51 {
  52     int ndx=mod_query_history_search(str, 0, FALSE, TRUE);
  53
  54     if(ndx==0){
  55         free(str);
  56         return; /* First entry already */
  57     }else if(ndx>0){
  58         int i, j;
  59         i=get_index(ndx);
  60         free(hist[i]);
  61         while(++ndx<hist_count){
  62             j=get_index(ndx);
  63             hist[i]=hist[j];
  64             i=j;
  65         }
  66         hist_count--;
  67     }
  68
  69     hist_head--;
  70     if(hist_head<0)
  71         hist_head=HISTORY_SIZE-1;
  72
  73     if(hist_count==HISTORY_SIZE)
  74         free(hist[hist_head]);
  75     else
  76         hist_count++;
  77
  78     hist[hist_head]=str;
  79 }
  80
  81
  82 /*EXTL_DOC
  83  * Get entry at index \var{n} in line editor history, 0 being the latest.
  84  */
  85 EXTL_SAFE
  86 EXTL_EXPORT
  87 const char *mod_query_history_get(int n)
  88 {
  89     int i=get_index(n);
  90     return (i<0 ? NULL : hist[i]);
  91 }
  92
  93
  94 /*EXTL_DOC
  95  * Clear line editor history.
  96  */
  97 EXTL_EXPORT
  98 void mod_query_history_clear()
  99 {
 100     while(hist_count!=0){
 101         free(hist[hist_head]);
 102         hist_count--;
 103         if(++hist_head==HISTORY_SIZE)
 104             hist_head=0;
 105     }
 106     hist_head=HISTORY_SIZE;
 107 }
 108
 109
 110
 111 static bool match(const char *h, const char *b, bool exact)
 112 {
 113     const char *h_;
 114
 115     if(b==NULL)
 116         return TRUE;
 117
 118     /* Special case: search in any context. */
 119     if(*b=='*' && *(b+1)==':'){
 120         b=b+2;
 121         h_=strchr(h, ':');
 122         if(h_!=NULL)
 123             h=h_+1;
 124     }
 125
 126     return (exact
 127             ? strcmp(h, b)==0
 128             : strncmp(h, b, strlen(b))==0);
 129 }
 130
 131
 132 static const char *skip_colon(const char *s)
 133 {
 134     const char *p=strchr(s, ':');
 135     return (p!=NULL ? p+1 : s);
 136 }
 137
 138
 139 /*EXTL_DOC
 140  * Try to find matching history entry. Returns -1 if none was
 141  * found. The parameter \var{from} specifies where to start
 142  * searching from, and \var{bwd} causes backward search from
 143  * that point. If \var{exact} is not set, \var{s} only required
 144  * to be a prefix of the match.
 145  */
 146 EXTL_SAFE
 147 EXTL_EXPORT
 148 int mod_query_history_search(const char *s, int from, bool bwd, bool exact)
 149 {
 150     while(1){
 151         int i=get_index(from);
 152         if(i<0)
 153             return -1;
 154         if(match(hist[i], s, exact))
 155             return from;
 156         if(bwd)
 157             from--;
 158         else
 159             from++;
 160     }
 161 }
 162
 163
 164 uint mod_query_history_complete(const char *s, char ***h_ret)
 165 {
 166     char **h=ALLOC_N(char *, hist_count);
 167     int i, n=0;
 168
 169     if(h==NULL)
 170         return 0;
 171
 172     for(i=0; i<hist_count; i++){
 173         int j=get_index(i);
 174         if(j<0)
 175             break;
 176         if(match(hist[j], s, FALSE)){
 177             h[n]=scopy(skip_colon(hist[j]));
 178             if(h[n]!=NULL)
 179                 n++;
 180         }
 181     }
 182
 183     if(n==0)
 184         free(h);
 185     else
 186         *h_ret=h;
 187
 188     return n;
 189 }
 190
 191
 192 /*EXTL_DOC
 193  * Return table of history entries.
 194  */
 195 EXTL_SAFE
 196 EXTL_EXPORT
 197 ExtlTab mod_query_history_table()
 198 {
 199     ExtlTab tab=extl_create_table();
 200     int i;
 201
 202     for(i=0; i<hist_count; i++){
 203         int j=get_index(i);
 204         extl_table_seti_s(tab, i+1, hist[j]);
 205     }
 206
 207     return tab;
 208 }