toybox/lib/linestack.c
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   1#include "toys.h"
   2
   3// The design idea here is indexing a big blob of (potentially mmaped) data
   4// instead of copying the data into a zillion seperate malloc()s.
   5
   6// A linestack is an array of struct ptr_len, with a currently used len
   7// and max tracking the memory allocation. This indexes existing string data,
   8// the lifetime of which is tracked externally.
   9
  10// Insert one stack into another before position in old stack.
  11// (Does not copy contents of strings, just shuffles index array contents.)
  12void linestack_addstack(struct linestack **lls, struct linestack *throw,
  13  long pos)
  14{
  15  struct linestack *catch = *lls;
  16
  17  if (CFG_TOYBOX_DEBUG)
  18    if (pos > catch->len) error_exit("linestack_addstack past end.");
  19
  20  // Make a hole, allocating more space if necessary.
  21  if (catch->len+throw->len >= catch->max) {
  22    // New size rounded up to next multiple of 64, allocate and copy start.
  23    catch->max = ((catch->len+throw->len)|63)+1;
  24    *lls = xmalloc(sizeof(struct linestack)+catch->max*sizeof(struct ptr_len));
  25    memcpy(*lls, catch, sizeof(struct linestack)+pos*sizeof(struct ptr_len));
  26  }
  27
  28  // Copy end (into new allocation if necessary)
  29  if (pos != catch->len)
  30    memmove((*lls)->idx+pos+throw->len, catch->idx+pos,
  31      (catch->len-pos)*sizeof(struct ptr_len));
  32
  33  // Cleanup if we had to realloc.
  34  if (catch != *lls) {
  35    free(catch);
  36    catch = *lls;
  37  }
  38
  39  // Copy new chunk we made space for
  40  memcpy(catch->idx+pos, throw->idx, throw->len*sizeof(struct ptr_len));
  41  catch->len += throw->len;
  42}
  43
  44// Insert one line/len into a linestack at pos
  45void linestack_insert(struct linestack **lls, long pos, char *line, long len)
  46{
  47  // alloca() was in 32V and Turbo C for DOS, but isn't in posix or c99.
  48  // This allocates enough memory for the linestack to have one ptr_len.
  49  // (Even if a compiler adds gratuitous padidng that just makes it bigger.)
  50  struct {
  51    struct ptr_len pl;
  52    struct linestack ls;
  53  } ls;
  54
  55  ls.ls.len = ls.ls.max = 1;
  56  ls.ls.idx[0].ptr = line;
  57  ls.ls.idx[0].len = len;
  58  linestack_addstack(lls, &ls.ls, pos);
  59}
  60
  61void linestack_append(struct linestack **lls, char *line)
  62{
  63  linestack_insert(lls, (*lls)->len, line, strlen(line));
  64}
  65
  66struct linestack *linestack_load(char *name)
  67{
  68  FILE *fp = fopen(name, "r");
  69  struct linestack *ls;
  70
  71  if (!fp) return 0;
  72
  73  ls = xzalloc(sizeof(struct linestack));
  74
  75  for (;;) {
  76    char *line = 0;
  77    ssize_t len;
  78
  79    if ((len = getline(&line, (void *)&len, fp))<1) break;
  80    if (line[len-1]=='\n') len--;
  81    linestack_insert(&ls, ls->len, line, len);
  82  }
  83  fclose(fp);
  84
  85  return ls;
  86}
  87
  88// Show width many columns, negative means from right edge, out=0 just measure
  89// if escout, send it unprintable chars, otherwise pass through raw data.
  90// Returns width in columns, moves *str to end of data consumed.
  91int crunch_str(char **str, int width, FILE *out, char *escmore,
  92  int (*escout)(FILE *out, int cols, int wc))
  93{
  94  int columns = 0, col, bytes;
  95  char *start, *end;
  96
  97  for (end = start = *str; *end; columns += col, end += bytes) {
  98    wchar_t wc;
  99
 100    if ((bytes = utf8towc(&wc, end, 4))>0 && (col = wcwidth(wc))>=0) {
 101      if (!escmore || wc>255 || !strchr(escmore, wc)) {
 102        if (width-columns<col) break;
 103        if (out) fwrite(end, bytes, 1, out);
 104
 105        continue;
 106      }
 107    }
 108
 109    if (bytes<1) {
 110      bytes = 1;
 111      wc = *end;
 112    }
 113    col = width-columns;
 114    if (col<1) break;
 115    if (escout) {
 116      if ((col = escout(out, col, wc))<0) break;
 117    } else if (out) fwrite(end, 1, bytes, out);
 118  }
 119  *str = end;
 120
 121  return columns;
 122}
 123
 124
 125// standard escapes: ^X if <32, <XX> if invalid UTF8, U+XXXX if UTF8 !iswprint()
 126int crunch_escape(FILE *out, int cols, int wc)
 127{
 128  char buf[8];
 129  int rc;
 130
 131  if (wc<' ') rc = sprintf(buf, "^%c", '@'+wc);
 132  else if (wc<256) rc = sprintf(buf, "<%02X>", wc);
 133  else rc = sprintf(buf, "U+%04X", wc);
 134
 135  if (rc > cols) buf[rc = cols] = 0;
 136  if (out) fputs(buf, out);
 137
 138  return rc;
 139}
 140
 141// Display "standard" escapes in reverse video.
 142int crunch_rev_escape(FILE *out, int cols, int wc)
 143{
 144  int rc;
 145
 146  tty_esc("7m");
 147  rc = crunch_escape(out, cols, wc);
 148  tty_esc("27m");
 149
 150  return rc;
 151}
 152
 153// Write width chars at start of string to strdout with standard escapes
 154// Returns length in columns so caller can pad it out with spaces.
 155int draw_str(char *start, int width)
 156{
 157  return crunch_str(&start, width, stdout, 0, crunch_rev_escape);
 158}
 159
 160// Return utf8 columns
 161int utf8len(char *str)
 162{
 163  return crunch_str(&str, INT_MAX, 0, 0, crunch_rev_escape);
 164}
 165
 166// Return bytes used by (up to) this many columns
 167int utf8skip(char *str, int width)
 168{
 169  char *s = str;
 170
 171  crunch_str(&s, width, 0, 0, crunch_rev_escape);
 172
 173  return s-str;
 174}
 175
 176// Print utf8 to stdout with standard escapes, trimmed to width and padded
 177// out to padto. If padto<0 left justify. Returns columns printed
 178int draw_trim_esc(char *str, int padto, int width, char *escmore,
 179  int (*escout)(FILE *out, int cols, int wc))
 180{
 181  int apad = abs(padto), len = utf8len(str);
 182
 183  if (padto>=0 && len>width) str += utf8skip(str, len-width);
 184  if (len>width) len = width;
 185
 186  // Left pad if right justified 
 187  if (padto>0 && apad>len) printf("%*s", apad-len, "");
 188  crunch_str(&str, len, stdout, 0, crunch_rev_escape);
 189  if (padto<0 && apad>len) printf("%*s", apad-len, "");
 190
 191  return (apad > len) ? apad : len;
 192}
 193
 194// draw_trim_esc() with default escape
 195int draw_trim(char *str, int padto, int width)
 196{
 197  return draw_trim_esc(str, padto, width, 0, 0);
 198}
 199