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-rw-r--r--libguile/strports.c181
1 files changed, 89 insertions, 92 deletions
diff --git a/libguile/strports.c b/libguile/strports.c
index 625b75308..b7fec4703 100644
--- a/libguile/strports.c
+++ b/libguile/strports.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995,1996,1998,1999,2000,2001,2002, 2003, 2005, 2006, 2009, 2010 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1998,1999,2000,2001,2002, 2003, 2005, 2006, 2009, 2010, 2011 Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
@@ -30,7 +30,7 @@
#include <unistd.h>
#endif
-#include "libguile/arrays.h"
+#include "libguile/bytevectors.h"
#include "libguile/eval.h"
#include "libguile/ports.h"
#include "libguile/read.h"
@@ -55,15 +55,8 @@
/* NOTES:
- We break the rules set forth by strings.h about accessing the
- internals of strings here. We can do this since we can guarantee
- that the string used as pt->stream is not in use by anyone else.
- Thus, it's representation will not change asynchronously.
-
- (Ports aren't thread-safe yet anyway...)
-
- write_buf/write_end point to the ends of the allocated string.
- read_buf/read_end in principle point to the part of the string which
+ write_buf/write_end point to the ends of the allocated bytevector.
+ read_buf/read_end in principle point to the part of the bytevector which
has been written to, but this is only updated after a flush.
read_pos and write_pos in principle should be equal, but this is only true
when rw_active is SCM_PORT_NEITHER.
@@ -106,25 +99,23 @@ stfill_buffer (SCM port)
return scm_return_first_int (*pt->read_pos, port);
}
-/* change the size of a port's string to new_size. this doesn't
- change read_buf_size. */
-static void
+/* Change the size of a port's bytevector to NEW_SIZE. This doesn't
+ change `read_buf_size'. */
+static void
st_resize_port (scm_t_port *pt, scm_t_off new_size)
{
SCM old_stream = SCM_PACK (pt->stream);
- const char *src = scm_i_string_chars (old_stream);
- char *dst;
- SCM new_stream = scm_i_make_string (new_size, &dst);
- unsigned long int old_size = scm_i_string_length (old_stream);
+ const signed char *src = SCM_BYTEVECTOR_CONTENTS (old_stream);
+ SCM new_stream = scm_c_make_bytevector (new_size);
+ signed char *dst = SCM_BYTEVECTOR_CONTENTS (new_stream);
+ unsigned long int old_size = SCM_BYTEVECTOR_LENGTH (old_stream);
unsigned long int min_size = min (old_size, new_size);
- unsigned long int i;
scm_t_off index = pt->write_pos - pt->write_buf;
pt->write_buf_size = new_size;
- for (i = 0; i != min_size; ++i)
- dst[i] = src[i];
+ memcpy (dst, src, min_size);
scm_remember_upto_here_1 (old_stream);
@@ -138,27 +129,17 @@ st_resize_port (scm_t_port *pt, scm_t_off new_size)
}
}
-/* amount by which write_buf is expanded. */
-#define SCM_WRITE_BLOCK 80
-
-/* ensure that write_pos < write_end by enlarging the buffer when
- necessary. update read_buf to account for written chars.
-
- The buffer is enlarged by 1.5 times, plus SCM_WRITE_BLOCK. Adding just a
- fixed amount is no good, because there's a block copy for each increment,
- and that copying would take quadratic time. In the past it was found to
- be very slow just adding 80 bytes each time (eg. about 10 seconds for
- writing a 100kbyte string). */
-
+/* Ensure that `write_pos' < `write_end' by enlarging the buffer when
+ necessary. Update `read_buf' to account for written chars. The
+ buffer is enlarged geometrically. */
static void
st_flush (SCM port)
{
scm_t_port *pt = SCM_PTAB_ENTRY (port);
if (pt->write_pos == pt->write_end)
- {
- st_resize_port (pt, pt->write_buf_size * 3 / 2 + SCM_WRITE_BLOCK);
- }
+ st_resize_port (pt, pt->write_buf_size * 2);
+
pt->read_pos = pt->write_pos;
if (pt->read_pos > pt->read_end)
{
@@ -255,12 +236,8 @@ st_seek (SCM port, scm_t_off offset, int whence)
SCM_EOL);
}
}
- else
- {
- st_resize_port (pt, target + (target == pt->write_buf_size
- ? SCM_WRITE_BLOCK
- : 0));
- }
+ else if (target == pt->write_buf_size)
+ st_resize_port (pt, target * 2);
}
pt->read_pos = pt->write_pos = pt->read_buf + target;
if (pt->read_pos > pt->read_end)
@@ -289,16 +266,19 @@ st_truncate (SCM port, scm_t_off length)
pt->write_pos = pt->read_end;
}
+/* The initial size in bytes of a string port's buffer. */
+#define INITIAL_BUFFER_SIZE 128
+
+/* Return a new string port with MODES. If STR is #f, a new backing
+ buffer is allocated; otherwise STR must be a string and a copy of it
+ serves as the buffer for the new port. */
SCM
scm_mkstrport (SCM pos, SCM str, long modes, const char *caller)
{
- SCM z;
+ SCM z, buf;
scm_t_port *pt;
size_t str_len, c_pos;
- char *buf, *c_str;
-
- SCM_ASSERT (scm_is_string (str), str, SCM_ARG1, caller);
- c_pos = scm_to_unsigned_integer (pos, 0, scm_i_string_length (str));
+ char *c_buf;
if (!((modes & SCM_WRTNG) || (modes & SCM_RDNG)))
scm_misc_error ("scm_mkstrport", "port must read or write", SCM_EOL);
@@ -308,19 +288,44 @@ scm_mkstrport (SCM pos, SCM str, long modes, const char *caller)
z = scm_new_port_table_entry (scm_tc16_strport);
pt = SCM_PTAB_ENTRY(z);
- SCM_SETSTREAM (z, SCM_UNPACK (str));
- SCM_SET_CELL_TYPE (z, scm_tc16_strport | modes);
- /* Create a copy of STR in the encoding of Z. */
- buf = scm_to_stringn (str, &str_len, pt->encoding,
- SCM_FAILED_CONVERSION_ERROR);
- c_str = scm_gc_malloc (str_len, "strport");
- memcpy (c_str, buf, str_len);
- free (buf);
+ if (scm_is_false (str))
+ {
+ /* Allocate a new buffer to write to. */
+ str_len = INITIAL_BUFFER_SIZE;
+ buf = scm_c_make_bytevector (str_len);
+ c_buf = (char *) SCM_BYTEVECTOR_CONTENTS (buf);
+
+ /* Reset `read_buf_size'. It will contain the actual number of
+ bytes written to PT. */
+ pt->read_buf_size = 0;
+ c_pos = 0;
+ }
+ else
+ {
+ /* STR is a string. */
+ char *copy;
+
+ SCM_ASSERT (scm_is_string (str), str, SCM_ARG1, caller);
+
+ /* Create a copy of STR in the encoding of PT. */
+ copy = scm_to_stringn (str, &str_len, pt->encoding,
+ SCM_FAILED_CONVERSION_ERROR);
+ buf = scm_c_make_bytevector (str_len);
+ c_buf = (char *) SCM_BYTEVECTOR_CONTENTS (buf);
+ memcpy (c_buf, copy, str_len);
+ free (copy);
- pt->write_buf = pt->read_buf = (unsigned char *) c_str;
+ c_pos = scm_to_unsigned_integer (pos, 0, str_len);
+ pt->read_buf_size = str_len;
+ }
+
+ SCM_SETSTREAM (z, SCM_UNPACK (buf));
+ SCM_SET_CELL_TYPE (z, scm_tc16_strport | modes);
+
+ pt->write_buf = pt->read_buf = (unsigned char *) c_buf;
pt->read_pos = pt->write_pos = pt->read_buf + c_pos;
- pt->write_buf_size = pt->read_buf_size = str_len;
+ pt->write_buf_size = str_len;
pt->write_end = pt->read_end = pt->read_buf + pt->read_buf_size;
pt->rw_random = 1;
@@ -352,7 +357,7 @@ scm_strport_to_string (SCM port)
if (pt->encoding == NULL)
{
char *buf;
- str = scm_i_make_string (pt->read_buf_size, &buf);
+ str = scm_i_make_string (pt->read_buf_size, &buf, 0);
memcpy (buf, pt->read_buf, pt->read_buf_size);
}
else
@@ -369,20 +374,30 @@ SCM_DEFINE (scm_object_to_string, "object->string", 1, 1, 0,
"argument @var{printer} (default: @code{write}).")
#define FUNC_NAME s_scm_object_to_string
{
- SCM str, port;
+ SCM port, result;
if (!SCM_UNBNDP (printer))
SCM_VALIDATE_PROC (2, printer);
- str = scm_c_make_string (0, SCM_UNDEFINED);
- port = scm_mkstrport (SCM_INUM0, str, SCM_OPN | SCM_WRTNG, FUNC_NAME);
+ port = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
+ SCM_OPN | SCM_WRTNG, FUNC_NAME);
if (SCM_UNBNDP (printer))
scm_write (obj, port);
else
scm_call_2 (printer, obj, port);
- return scm_strport_to_string (port);
+ result = scm_strport_to_string (port);
+
+ /* Explicitly close PORT so that the iconv CDs associated with it are
+ deallocated right away. This is important because CDs use a lot of
+ memory that's not visible to the GC, so not freeing them can lead
+ to almost large heap usage. See
+ <http://wingolog.org/archives/2011/02/25/ports-weaks-gc-and-dark-matter>
+ for details. */
+ scm_close_port (port);
+
+ return result;
}
#undef FUNC_NAME
@@ -395,8 +410,7 @@ SCM_DEFINE (scm_call_with_output_string, "call-with-output-string", 1, 0, 0,
{
SCM p;
- p = scm_mkstrport (SCM_INUM0,
- scm_make_string (SCM_INUM0, SCM_UNDEFINED),
+ p = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
SCM_OPN | SCM_WRTNG,
FUNC_NAME);
scm_call_1 (proc, p);
@@ -441,8 +455,7 @@ SCM_DEFINE (scm_open_output_string, "open-output-string", 0, 0, 0,
{
SCM p;
- p = scm_mkstrport (SCM_INUM0,
- scm_make_string (SCM_INUM0, SCM_UNDEFINED),
+ p = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
SCM_OPN | SCM_WRTNG,
FUNC_NAME);
return p;
@@ -467,15 +480,12 @@ SCM_DEFINE (scm_get_output_string, "get-output-string", 1, 0, 0,
SCM
scm_c_read_string (const char *expr)
{
- /* FIXME: the c string gets packed into a string, only to get
- immediately unpacked in scm_mkstrport. */
SCM port = scm_mkstrport (SCM_INUM0,
scm_from_locale_string (expr),
SCM_OPN | SCM_RDNG,
"scm_c_read_string");
SCM form;
- /* Read expressions from that port; ignore the values. */
form = scm_read (port);
scm_close_port (port);
@@ -497,25 +507,6 @@ scm_c_eval_string_in_module (const char *expr, SCM module)
}
-static SCM
-inner_eval_string (void *data)
-{
- SCM port = (SCM)data;
- SCM form;
- SCM ans = SCM_UNSPECIFIED;
-
- /* Read expressions from that port; ignore the values. */
- while (!SCM_EOF_OBJECT_P (form = scm_read (port)))
- ans = scm_primitive_eval_x (form);
-
- /* Don't close the port here; if we re-enter this function via a
- continuation, then the next time we enter it, we'll get an error.
- It's a string port anyway, so there's no advantage to closing it
- early. */
-
- return ans;
-}
-
SCM_DEFINE (scm_eval_string_in_module, "eval-string", 1, 1, 0,
(SCM string, SCM module),
"Evaluate @var{string} as the text representation of a Scheme\n"
@@ -527,14 +518,20 @@ SCM_DEFINE (scm_eval_string_in_module, "eval-string", 1, 1, 0,
"procedure returns.")
#define FUNC_NAME s_scm_eval_string_in_module
{
- SCM port = scm_mkstrport (SCM_INUM0, string, SCM_OPN | SCM_RDNG,
- FUNC_NAME);
+ static SCM eval_string = SCM_BOOL_F, k_module = SCM_BOOL_F;
+
+ if (scm_is_false (eval_string))
+ {
+ eval_string = scm_c_public_lookup ("ice-9 eval-string", "eval-string");
+ k_module = scm_from_locale_keyword ("module");
+ }
+
if (SCM_UNBNDP (module))
module = scm_current_module ();
else
SCM_VALIDATE_MODULE (2, module);
- return scm_c_call_with_current_module (module,
- inner_eval_string, (void *)port);
+
+ return scm_call_3 (scm_variable_ref (eval_string), string, k_module, module);
}
#undef FUNC_NAME