sb: add some utilities like prepend, free, steal…

src/bin/sb.c

@@ -10,15 +10,15 @@ ty_sb_add(struct ty_sb *sb, const char *s, size_t len)
 {
    size_t new_len = sb->len + len;
 
-   if ((new_len >= sb->alloc) || !sb->buf)
+   if ((new_len + sb->gap >= sb->alloc) || !sb->buf)
      {
-        size_t new_alloc = ((new_len + 15) / 16) * 24;
+        size_t new_alloc = ((new_len + sb->gap + 15) / 16) * 24;
         char *new_buf;
 
-        new_buf = realloc(sb->buf, new_alloc);
+        new_buf = realloc(sb->buf - sb->gap, new_alloc);
         if (new_buf == NULL)
           return -1;
-        sb->buf = new_buf;
+        sb->buf = new_buf + sb->gap;
         sb->alloc = new_alloc;
      }
    memcpy(sb->buf + sb->len, s, len);
@@ -27,6 +27,35 @@ ty_sb_add(struct ty_sb *sb, const char *s, size_t len)
    return 0;
 }
 
+int
+ty_sb_prepend(struct ty_sb *sb, const char *s, size_t  len)
+{
+   if (len >= sb->gap)
+     {
+        size_t aligned_gap = ((len + 15) / 16) * 24;
+        size_t third_of_alloc = (((sb->alloc / 3) + 15) / 16) * 16;
+        size_t new_gap = MAX(aligned_gap, third_of_alloc);
+        size_t new_alloc = sb->alloc + new_gap;
+        char *new_buf;
+
+        new_buf = calloc(new_alloc, 1);
+        if (new_buf == NULL)
+          return -1;
+
+        memcpy(new_buf + new_gap, sb->buf, sb->len);
+        sb->buf = new_buf + new_gap;
+        sb->gap = new_gap;
+        sb->alloc = new_alloc;
+     }
+
+   sb->buf -= len;
+   sb->gap -= len;
+   sb->len += len;
+   memcpy(sb->buf, s, len);
+   return 0;
+}
+
+
 /* unlike eina_strbuf_rtrim, only trims \t, \f, ' ' */
 void
 ty_sb_spaces_rtrim(struct ty_sb *sb)
@@ -43,3 +72,53 @@ ty_sb_spaces_rtrim(struct ty_sb *sb)
      }
    sb->buf[sb->len] = '\0';
 }
+
+char *
+ty_sb_steal_buf(struct ty_sb *sb)
+{
+   size_t i;
+   char *buf;
+
+   if (sb->gap != 0)
+     {
+        sb->buf -= sb->gap;
+        for (i = 0; i <= sb->len; i++)
+          {
+             sb->buf[i] = sb->buf[i + sb->gap];
+          }
+        sb->gap = 0;
+     }
+
+   sb->alloc = 0;
+   sb->gap = 0;
+   sb->len = 0;
+
+   buf = sb->buf;
+
+   sb->buf = NULL;
+
+   return buf;
+}
+
+void
+ty_sb_lskip(struct ty_sb *sb, int len)
+{
+   sb->len -= len;
+   sb->gap += len;
+   sb->buf += len;
+}
+
+void
+ty_sb_rskip(struct ty_sb *sb, int len)
+{
+   sb->len -= len;
+   sb->buf[sb->len] = '\0';
+}
+
+void
+ty_sb_free(struct ty_sb *sb)
+{
+   free(sb->buf - sb->gap);
+   sb->gap = sb->len = sb->alloc = 0;
+   sb->buf = NULL;
+}

src/bin/sb.h

@@ -5,13 +5,17 @@
 
 struct ty_sb {
    char *buf;
+   size_t gap;
    size_t len;
    size_t alloc;
 };
 
-int
+int ty_sb_add(struct ty_sb *sb, const char *s, size_t len);
-ty_sb_add(struct ty_sb *sb, const char *s, size_t len);
+void ty_sb_spaces_rtrim(struct ty_sb *sb);
-void
+int ty_sb_prepend(struct ty_sb *sb, const char *s, size_t  len);
-ty_sb_spaces_rtrim(struct ty_sb *sb);
+char *ty_sb_steal_buf(struct ty_sb *sb);
+void ty_sb_lskip(struct ty_sb *sb, int len);
+void ty_sb_rskip(struct ty_sb *sb, int len);
+void ty_sb_free(struct ty_sb *sb);
 
 #endif

src/bin/termio.c

@@ -2192,9 +2192,10 @@ termio_selection_get(Evas_Object *obj, int c1x, int c1y, int c2x, int c2y,
    if (lenp)
      *lenp = sb.len;
 
-   return sb.buf;
+   return ty_sb_steal_buf(&sb);
+
 err:
-   free(sb.buf);
+   ty_sb_free(&sb);
    return NULL;
 }