--- /dev/null
+/* Copyright (C) 1995,1996,1998,1999,2000,2001,2002, 2003, 2005, 2006 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 as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+\f
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libguile/_scm.h"
+
+#include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "libguile/unif.h"
+#include "libguile/eval.h"
+#include "libguile/ports.h"
+#include "libguile/read.h"
+#include "libguile/root.h"
+#include "libguile/strings.h"
+#include "libguile/modules.h"
+#include "libguile/validate.h"
+#include "libguile/deprecation.h"
+
+#include "libguile/strports.h"
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+\f
+
+/* {Ports - string ports}
+ *
+ */
+
+/* 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
+ 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.
+
+ ENHANCE-ME - output blocks:
+
+ The current code keeps an output string as a single block. That means
+ when the size is increased the entire old contents must be copied. It'd
+ be more efficient to begin a new block when the old one is full, so
+ there's no re-copying of previous data.
+
+ To make seeking efficient, keeping the pieces in a vector might be best,
+ though appending is probably the most common operation. The size of each
+ block could be progressively increased, so the bigger the string the
+ bigger the blocks.
+
+ When `get-output-string' is called the blocks have to be coalesced into a
+ string, the result could be kept as a single big block. If blocks were
+ strings then `get-output-string' could notice when there's just one and
+ return that with a copy-on-write (though repeated calls to
+ `get-output-string' are probably unlikely).
+
+ Another possibility would be to extend the port mechanism to let SCM
+ strings come through directly from `display' and friends. That way if a
+ big string is written it can be kept as a copy-on-write, saving time
+ copying and maybe saving some space. */
+
+
+scm_t_bits scm_tc16_strport;
+
+
+static int
+stfill_buffer (SCM port)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+
+ if (pt->read_pos >= pt->read_end)
+ return EOF;
+ else
+ 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
+st_resize_port (scm_t_port *pt, off_t 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);
+ unsigned long int min_size = min (old_size, new_size);
+ unsigned long int i;
+
+ off_t index = pt->write_pos - pt->write_buf;
+
+ pt->write_buf_size = new_size;
+
+ for (i = 0; i != min_size; ++i)
+ dst[i] = src[i];
+
+ scm_remember_upto_here_1 (old_stream);
+
+ /* reset buffer. */
+ {
+ pt->stream = SCM_UNPACK (new_stream);
+ pt->read_buf = pt->write_buf = (unsigned char *)dst;
+ pt->read_pos = pt->write_pos = pt->write_buf + index;
+ pt->write_end = pt->write_buf + pt->write_buf_size;
+ pt->read_end = pt->read_buf + pt->read_buf_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). */
+
+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);
+ }
+ pt->read_pos = pt->write_pos;
+ if (pt->read_pos > pt->read_end)
+ {
+ pt->read_end = (unsigned char *) pt->read_pos;
+ pt->read_buf_size = pt->read_end - pt->read_buf;
+ }
+ pt->rw_active = SCM_PORT_NEITHER;
+}
+
+static void
+st_write (SCM port, const void *data, size_t size)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ const char *input = (char *) data;
+
+ while (size > 0)
+ {
+ int space = pt->write_end - pt->write_pos;
+ int write_len = (size > space) ? space : size;
+
+ memcpy ((char *) pt->write_pos, input, write_len);
+ pt->write_pos += write_len;
+ size -= write_len;
+ input += write_len;
+ if (write_len == space)
+ st_flush (port);
+ }
+}
+
+static void
+st_end_input (SCM port, int offset)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+
+ if (pt->read_pos - pt->read_buf < offset)
+ scm_misc_error ("st_end_input", "negative position", SCM_EOL);
+
+ pt->write_pos = (unsigned char *) (pt->read_pos = pt->read_pos - offset);
+ pt->rw_active = SCM_PORT_NEITHER;
+}
+
+static off_t
+st_seek (SCM port, off_t offset, int whence)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ off_t target;
+
+ if (pt->rw_active == SCM_PORT_READ && offset == 0 && whence == SEEK_CUR)
+ /* special case to avoid disturbing the unread-char buffer. */
+ {
+ if (pt->read_buf == pt->putback_buf)
+ {
+ target = pt->saved_read_pos - pt->saved_read_buf
+ - (pt->read_end - pt->read_pos);
+ }
+ else
+ {
+ target = pt->read_pos - pt->read_buf;
+ }
+ }
+ else
+ /* all other cases. */
+ {
+ if (pt->rw_active == SCM_PORT_WRITE)
+ st_flush (port);
+
+ if (pt->rw_active == SCM_PORT_READ)
+ scm_end_input (port);
+
+ switch (whence)
+ {
+ case SEEK_CUR:
+ target = pt->read_pos - pt->read_buf + offset;
+ break;
+ case SEEK_END:
+ target = pt->read_end - pt->read_buf + offset;
+ break;
+ default: /* SEEK_SET */
+ target = offset;
+ break;
+ }
+
+ if (target < 0)
+ scm_misc_error ("st_seek", "negative offset", SCM_EOL);
+
+ if (target >= pt->write_buf_size)
+ {
+ if (!(SCM_CELL_WORD_0 (port) & SCM_WRTNG))
+ {
+ if (target > pt->write_buf_size)
+ {
+ scm_misc_error ("st_seek",
+ "seek past end of read-only strport",
+ SCM_EOL);
+ }
+ }
+ else
+ {
+ st_resize_port (pt, target + (target == pt->write_buf_size
+ ? SCM_WRITE_BLOCK
+ : 0));
+ }
+ }
+ pt->read_pos = pt->write_pos = pt->read_buf + target;
+ if (pt->read_pos > pt->read_end)
+ {
+ pt->read_end = (unsigned char *) pt->read_pos;
+ pt->read_buf_size = pt->read_end - pt->read_buf;
+ }
+ }
+ return target;
+}
+
+static void
+st_truncate (SCM port, off_t length)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+
+ if (length > pt->write_buf_size)
+ st_resize_port (pt, length);
+
+ pt->read_buf_size = length;
+ pt->read_end = pt->read_buf + length;
+ if (pt->read_pos > pt->read_end)
+ pt->read_pos = pt->read_end;
+
+ if (pt->write_pos > pt->read_end)
+ pt->write_pos = pt->read_end;
+}
+
+SCM
+scm_mkstrport (SCM pos, SCM str, long modes, const char *caller)
+{
+ SCM z;
+ scm_t_port *pt;
+ size_t str_len, c_pos;
+
+ SCM_ASSERT (scm_is_string (str), str, SCM_ARG1, caller);
+
+ str_len = scm_i_string_length (str);
+ c_pos = scm_to_unsigned_integer (pos, 0, str_len);
+
+ if (!((modes & SCM_WRTNG) || (modes & SCM_RDNG)))
+ scm_misc_error ("scm_mkstrport", "port must read or write", SCM_EOL);
+
+ /* XXX
+
+ Make a new string to isolate us from changes to the original.
+ This is done so that we can rely on scm_i_string_chars to stay in
+ place even across SCM_TICKs.
+
+ Additionally, when we are going to write to the string, we make a
+ copy so that we can write to it without having to use
+ scm_i_string_writable_chars.
+ */
+
+ if (modes & SCM_WRTNG)
+ str = scm_c_substring_copy (str, 0, str_len);
+ else
+ str = scm_c_substring (str, 0, str_len);
+
+ scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
+ 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);
+ /* see above why we can use scm_i_string_chars here. */
+ pt->write_buf = pt->read_buf = (unsigned char *) scm_i_string_chars (str);
+ pt->read_pos = pt->write_pos = pt->read_buf + c_pos;
+ pt->write_buf_size = pt->read_buf_size = str_len;
+ pt->write_end = pt->read_end = pt->read_buf + pt->read_buf_size;
+
+ pt->rw_random = 1;
+
+ scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
+
+ /* ensure write_pos is writable. */
+ if ((modes & SCM_WRTNG) && pt->write_pos == pt->write_end)
+ st_flush (z);
+ return z;
+}
+
+/* create a new string from a string port's buffer. */
+SCM scm_strport_to_string (SCM port)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ SCM str;
+ char *dst;
+
+ if (pt->rw_active == SCM_PORT_WRITE)
+ st_flush (port);
+
+ str = scm_i_make_string (pt->read_buf_size, &dst);
+ memcpy (dst, (char *) pt->read_buf, pt->read_buf_size);
+ scm_remember_upto_here_1 (port);
+ return str;
+}
+
+SCM_DEFINE (scm_object_to_string, "object->string", 1, 1, 0,
+ (SCM obj, SCM printer),
+ "Return a Scheme string obtained by printing @var{obj}.\n"
+ "Printing function can be specified by the optional second\n"
+ "argument @var{printer} (default: @code{write}).")
+#define FUNC_NAME s_scm_object_to_string
+{
+ SCM str, port;
+
+ 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);
+
+ if (SCM_UNBNDP (printer))
+ scm_write (obj, port);
+ else
+ scm_call_2 (printer, obj, port);
+
+ return scm_strport_to_string (port);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_call_with_output_string, "call-with-output-string", 1, 0, 0,
+ (SCM proc),
+ "Calls the one-argument procedure @var{proc} with a newly created output\n"
+ "port. When the function returns, the string composed of the characters\n"
+ "written into the port is returned.")
+#define FUNC_NAME s_scm_call_with_output_string
+{
+ SCM p;
+
+ p = scm_mkstrport (SCM_INUM0,
+ scm_make_string (SCM_INUM0, SCM_UNDEFINED),
+ SCM_OPN | SCM_WRTNG,
+ FUNC_NAME);
+ scm_call_1 (proc, p);
+
+ return scm_get_output_string (p);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_call_with_input_string, "call-with-input-string", 2, 0, 0,
+ (SCM string, SCM proc),
+ "Calls the one-argument procedure @var{proc} with a newly\n"
+ "created input port from which @var{string}'s contents may be\n"
+ "read. The value yielded by the @var{proc} is returned.")
+#define FUNC_NAME s_scm_call_with_input_string
+{
+ SCM p = scm_mkstrport(SCM_INUM0, string, SCM_OPN | SCM_RDNG, FUNC_NAME);
+ return scm_call_1 (proc, p);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_open_input_string, "open-input-string", 1, 0, 0,
+ (SCM str),
+ "Take a string and return an input port that delivers characters\n"
+ "from the string. The port can be closed by\n"
+ "@code{close-input-port}, though its storage will be reclaimed\n"
+ "by the garbage collector if it becomes inaccessible.")
+#define FUNC_NAME s_scm_open_input_string
+{
+ SCM p = scm_mkstrport(SCM_INUM0, str, SCM_OPN | SCM_RDNG, FUNC_NAME);
+ return p;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_open_output_string, "open-output-string", 0, 0, 0,
+ (void),
+ "Return an output port that will accumulate characters for\n"
+ "retrieval by @code{get-output-string}. The port can be closed\n"
+ "by the procedure @code{close-output-port}, though its storage\n"
+ "will be reclaimed by the garbage collector if it becomes\n"
+ "inaccessible.")
+#define FUNC_NAME s_scm_open_output_string
+{
+ SCM p;
+
+ p = scm_mkstrport (SCM_INUM0,
+ scm_make_string (SCM_INUM0, SCM_UNDEFINED),
+ SCM_OPN | SCM_WRTNG,
+ FUNC_NAME);
+ return p;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_get_output_string, "get-output-string", 1, 0, 0,
+ (SCM port),
+ "Given an output port created by @code{open-output-string},\n"
+ "return a string consisting of the characters that have been\n"
+ "output to the port so far.")
+#define FUNC_NAME s_scm_get_output_string
+{
+ SCM_VALIDATE_OPOUTSTRPORT (1, port);
+ return scm_strport_to_string (port);
+}
+#undef FUNC_NAME
+
+
+/* Given a null-terminated string EXPR containing a Scheme expression
+ read it, and return it as an SCM value. */
+SCM
+scm_c_read_string (const char *expr)
+{
+ 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);
+ return form;
+}
+
+/* Given a null-terminated string EXPR containing Scheme program text,
+ evaluate it, and return the result of the last expression evaluated. */
+SCM
+scm_c_eval_string (const char *expr)
+{
+ return scm_eval_string (scm_from_locale_string (expr));
+}
+
+SCM
+scm_c_eval_string_in_module (const char *expr, SCM module)
+{
+ return scm_eval_string_in_module (scm_from_locale_string (expr), 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"
+ "form or forms, and return whatever value they produce.\n"
+ "Evaluation takes place in the given module, or the current\n"
+ "module when no module is given.\n"
+ "While the code is evaluated, the given module is made the\n"
+ "current one. The current module is restored when this\n"
+ "procedure returns.")
+#define FUNC_NAME s_scm_eval_string_in_module
+{
+ SCM port = scm_mkstrport (SCM_INUM0, string, SCM_OPN | SCM_RDNG,
+ FUNC_NAME);
+ 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);
+}
+#undef FUNC_NAME
+
+SCM
+scm_eval_string (SCM string)
+{
+ return scm_eval_string_in_module (string, SCM_UNDEFINED);
+}
+
+static scm_t_bits
+scm_make_stptob ()
+{
+ scm_t_bits tc = scm_make_port_type ("string", stfill_buffer, st_write);
+
+ scm_set_port_mark (tc, scm_markstream);
+ scm_set_port_end_input (tc, st_end_input);
+ scm_set_port_flush (tc, st_flush);
+ scm_set_port_seek (tc, st_seek);
+ scm_set_port_truncate (tc, st_truncate);
+
+ return tc;
+}
+
+void
+scm_init_strports ()
+{
+ scm_tc16_strport = scm_make_stptob ();
+
+#include "libguile/strports.x"
+}
+
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
projects / lilypond.git / blobdiff