\f
-void
-scm_unget_byte (int c, SCM port)
-#define FUNC_NAME "scm_unget_byte"
+static void
+scm_i_unget_bytes (const unsigned char *buf, size_t len, SCM port)
+#define FUNC_NAME "scm_unget_bytes"
{
scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ size_t old_len, new_len;
scm_i_clear_pending_eof (port);
- if (pt->read_buf == pt->putback_buf)
- /* already using the put-back buffer. */
- {
- /* enlarge putback_buf if necessary. */
- if (pt->read_end == pt->read_buf + pt->read_buf_size
- && pt->read_buf == pt->read_pos)
- {
- size_t new_size = pt->read_buf_size * 2;
- unsigned char *tmp = (unsigned char *)
- scm_gc_realloc (pt->putback_buf, pt->read_buf_size, new_size,
- "putback buffer");
-
- pt->read_pos = pt->read_buf = pt->putback_buf = tmp;
- pt->read_end = pt->read_buf + pt->read_buf_size;
- pt->read_buf_size = pt->putback_buf_size = new_size;
- }
- /* shift any existing bytes to buffer + 1. */
- if (pt->read_pos == pt->read_end)
- pt->read_end = pt->read_buf + 1;
- else if (pt->read_pos != pt->read_buf + 1)
- {
- int count = pt->read_end - pt->read_pos;
-
- memmove (pt->read_buf + 1, pt->read_pos, count);
- pt->read_end = pt->read_buf + 1 + count;
- }
-
- pt->read_pos = pt->read_buf;
- }
- else
+ if (pt->read_buf != pt->putback_buf)
/* switch to the put-back buffer. */
{
if (pt->putback_buf == NULL)
{
+ pt->putback_buf_size = (len > SCM_INITIAL_PUTBACK_BUF_SIZE
+ ? len : SCM_INITIAL_PUTBACK_BUF_SIZE);
pt->putback_buf
= (unsigned char *) scm_gc_malloc_pointerless
- (SCM_INITIAL_PUTBACK_BUF_SIZE, "putback buffer");
- pt->putback_buf_size = SCM_INITIAL_PUTBACK_BUF_SIZE;
+ (pt->putback_buf_size, "putback buffer");
}
pt->saved_read_buf = pt->read_buf;
pt->saved_read_end = pt->read_end;
pt->saved_read_buf_size = pt->read_buf_size;
- pt->read_pos = pt->read_buf = pt->putback_buf;
- pt->read_end = pt->read_buf + 1;
+ /* Put read_pos at the end of the buffer, so that ungets will not
+ have to shift the buffer contents each time. */
+ pt->read_buf = pt->putback_buf;
+ pt->read_pos = pt->read_end = pt->putback_buf + pt->putback_buf_size;
pt->read_buf_size = pt->putback_buf_size;
}
- *pt->read_buf = c;
+ old_len = pt->read_end - pt->read_pos;
+ new_len = old_len + len;
+
+ if (new_len > pt->read_buf_size)
+ /* The putback buffer needs to be enlarged. */
+ {
+ size_t new_buf_size;
+ unsigned char *new_buf, *new_end, *new_pos;
+
+ new_buf_size = pt->read_buf_size * 2;
+ if (new_buf_size < new_len)
+ new_buf_size = new_len;
+
+ new_buf = (unsigned char *)
+ scm_gc_malloc_pointerless (new_buf_size, "putback buffer");
+
+ /* Put the bytes at the end of the buffer, so that future
+ ungets won't need to shift the buffer. */
+ new_end = new_buf + new_buf_size;
+ new_pos = new_end - old_len;
+ memcpy (new_pos, pt->read_pos, old_len);
+
+ pt->read_buf = pt->putback_buf = new_buf;
+ pt->read_pos = new_pos;
+ pt->read_end = new_end;
+ pt->read_buf_size = pt->putback_buf_size = new_buf_size;
+ }
+ else if (pt->read_buf + len < pt->read_pos)
+ /* If needed, shift the existing buffer contents up.
+ This should not happen unless some external code
+ manipulates the putback buffer pointers. */
+ {
+ unsigned char *new_end = pt->read_buf + pt->read_buf_size;
+ unsigned char *new_pos = new_end - old_len;
+
+ memmove (new_pos, pt->read_pos, old_len);
+ pt->read_pos = new_pos;
+ pt->read_end = new_end;
+ }
+
+ /* Move read_pos back and copy the bytes there. */
+ pt->read_pos -= len;
+ memcpy (pt->read_buf + (pt->read_pos - pt->read_buf), buf, len);
+
+ if (pt->rw_active == SCM_PORT_WRITE)
+ scm_flush (port);
if (pt->rw_random)
pt->rw_active = SCM_PORT_READ;
}
#undef FUNC_NAME
+void
+scm_unget_bytes (const unsigned char *buf, size_t len, SCM port)
+{
+ scm_i_unget_bytes (buf, len, port);
+}
+
+void
+scm_unget_byte (int c, SCM port)
+{
+ unsigned char byte;
+
+ byte = c;
+ scm_i_unget_bytes (&byte, 1, port);
+}
+
void
scm_ungetc (scm_t_wchar c, SCM port)
#define FUNC_NAME "scm_ungetc"
char result_buf[10];
const char *encoding;
size_t len;
- int i;
if (pt->encoding != NULL)
encoding = pt->encoding;
"conversion to port encoding failed",
SCM_BOOL_F, SCM_MAKE_CHAR (c));
- for (i = len - 1; i >= 0; i--)
- scm_unget_byte (result[i], port);
+ scm_i_unget_bytes ((unsigned char *) result, len, port);
if (SCM_UNLIKELY (result != result_buf))
free (result);
SCM result;
scm_t_wchar c;
char bytes[SCM_MBCHAR_BUF_SIZE];
- long column, line, i;
+ long column, line;
size_t len;
if (SCM_UNBNDP (port))
err = get_codepoint (port, &c, bytes, &len);
- for (i = len - 1; i >= 0; i--)
- scm_unget_byte (bytes[i], port);
+ scm_i_unget_bytes ((unsigned char *) bytes, len, port);
SCM_COL (port) = column;
SCM_LINUM (port) = line;
looking_at_bytes (SCM port, const unsigned char *bytes, int len)
{
scm_t_port *pt = SCM_PTAB_ENTRY (port);
- int result;
int i = 0;
while (i < len && scm_peek_byte_or_eof (port) == bytes[i])
pt->read_pos++;
i++;
}
-
- result = (i == len);
-
- while (i > 0)
- scm_unget_byte (bytes[--i], port);
-
- return result;
+ scm_i_unget_bytes (bytes, i, port);
+ return (i == len);
}
static const unsigned char scm_utf8_bom[3] = {0xEF, 0xBB, 0xBF};
HCoop / bpt / guile.git / blobdiff