From 00cde353baf5393ea2f5b19780090e4c6537af77 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Thu, 28 May 2015 23:28:55 +0900
Subject: [PATCH] xfile completely refactored

---
 extlib/benz/include/picrin.h        |   2 -
 extlib/benz/include/picrin/config.h |   1 +
 extlib/benz/include/picrin/xfile.h  | 694 ++++------------------------
 extlib/benz/port.c                  |  89 ++--
 extlib/benz/read.c                  |   9 +-
 extlib/benz/state.c                 |  10 +-
 extlib/benz/xfile.c                 | 472 +++++++++++++++++++
 7 files changed, 606 insertions(+), 671 deletions(-)
 create mode 100644 extlib/benz/xfile.c

diff --git a/extlib/benz/include/picrin.h b/extlib/benz/include/picrin.h
index 19fe9e16..c5fa86a9 100644
--- a/extlib/benz/include/picrin.h
+++ b/extlib/benz/include/picrin.h
@@ -32,8 +32,6 @@ extern "C" {
 #include <limits.h>
 #include <stdarg.h>
 
-#include <stdio.h>
-
 #include "picrin/config.h"
 #include "picrin/util.h"
 #include "picrin/compat.h"
diff --git a/extlib/benz/include/picrin/config.h b/extlib/benz/include/picrin/config.h
index 1de25976..a0274422 100644
--- a/extlib/benz/include/picrin/config.h
+++ b/extlib/benz/include/picrin/config.h
@@ -156,6 +156,7 @@
 #endif
 
 #if DEBUG
+# include <stdio.h>
 # define GC_STRESS 0
 # define VM_DEBUG 1
 # define GC_DEBUG 0
diff --git a/extlib/benz/include/picrin/xfile.h b/extlib/benz/include/picrin/xfile.h
index cce8fd05..eff7d269 100644
--- a/extlib/benz/include/picrin/xfile.h
+++ b/extlib/benz/include/picrin/xfile.h
@@ -5,632 +5,104 @@
 extern "C" {
 #endif
 
+#include <stdio.h>
+
+#ifndef NULL
+# define NULL 0
+#endif
+
+#ifndef EOF
+# define EOF (-1)
+#endif
+
+#define XBUFSIZ 1024
+#define XOPEN_MAX 1024
+
 typedef struct {
-  int ungot;
-  int flags;
+  /* buffer */
+  char buf[1];                  /* fallback buffer */
+  long cnt;                     /* characters left */
+  char *ptr;                    /* next character position */
+  char *base;                   /* location of the buffer */
   /* operators */
   struct {
     void *cookie;
     int (*read)(void *, char *, int);
     int (*write)(void *, const char *, int);
     long (*seek)(void *, long, int);
-    int (*flush)(void *);
     int (*close)(void *);
   } vtable;
+  int flag;                     /* mode of the file access */
 } xFILE;
 
-/* generic file constructor */
-PIC_INLINE xFILE *xfunopen(void *cookie, int (*read)(void *, char *, int), int (*write)(void *, const char *, int), long (*seek)(void *, long, int), int (*flush)(void *), int (*close)(void *));
+extern xFILE x_iob[XOPEN_MAX];
 
-/* resource aquisition */
-PIC_INLINE xFILE *xfpopen(FILE *);
-PIC_INLINE xFILE *xmopen();
-PIC_INLINE xFILE *xfopen(const char *, const char *);
-PIC_INLINE int xfclose(xFILE *);
+#define xstdin  (x_iob[0].vtable.cookie || (x_iob[0].vtable.cookie = stdin ), &x_iob[0])
+#define xstdout (x_iob[1].vtable.cookie || (x_iob[1].vtable.cookie = stdout), &x_iob[1])
+#define xstderr (x_iob[2].vtable.cookie || (x_iob[2].vtable.cookie = stderr), &x_iob[2])
 
-/* buffer management */
-PIC_INLINE int xfflush(xFILE *);
-
-/* direct IO with buffering */
-PIC_INLINE size_t xfread(void *, size_t, size_t, xFILE *);
-PIC_INLINE size_t xfwrite(const void *, size_t, size_t, xFILE *);
-
-/* indicator positioning */
-PIC_INLINE long xfseek(xFILE *, long offset, int whence);
-PIC_INLINE long xftell(xFILE *);
-PIC_INLINE void xrewind(xFILE *);
-
-/* stream status */
-PIC_INLINE void xclearerr(xFILE *);
-PIC_INLINE int xfeof(xFILE *);
-PIC_INLINE int xferror(xFILE *);
-
-/* character IO */
-PIC_INLINE int xfgetc(xFILE *);
-PIC_INLINE char *xfgets(char *, int, xFILE *);
-PIC_INLINE int xfputc(int, xFILE *);
-PIC_INLINE int xfputs(const char *, xFILE *);
-PIC_INLINE int xgetc(xFILE *);
-PIC_INLINE int xgetchar(void);
-PIC_INLINE int xputc(int, xFILE *);
-PIC_INLINE int xputchar(int);
-PIC_INLINE int xputs(const char *);
-PIC_INLINE int xungetc(int, xFILE *);
-
-/* formatted I/O */
-PIC_INLINE int xprintf(const char *, ...);
-PIC_INLINE int xfprintf(xFILE *, const char *, ...);
-PIC_INLINE int xvfprintf(xFILE *, const char *, va_list);
-
-/* standard I/O */
-#define xstdin (xstdin_())
-#define xstdout (xstdout_())
-#define xstderr (xstderr_())
-
-
-/* private */
-
-#define XF_EOF 1
-#define XF_ERR 2
-
-PIC_INLINE xFILE *
-xfunopen(void *cookie, int (*read)(void *, char *, int), int (*write)(void *, const char *, int), long (*seek)(void *, long, int), int (*flush)(void *), int (*close)(void *))
-{
-  xFILE *file;
-
-  file = (xFILE *)malloc(sizeof(xFILE));
-  if (! file) {
-    return NULL;
-  }
-  file->ungot = -1;
-  file->flags = 0;
-  /* set vtable */
-  file->vtable.cookie = cookie;
-  file->vtable.read = read;
-  file->vtable.write = write;
-  file->vtable.seek = seek;
-  file->vtable.flush = flush;
-  file->vtable.close = close;
-
-  return file;
-}
-
-/*
- * Derieved xFILE Classes
- */
-
-PIC_INLINE int
-xf_file_read(void *cookie, char *ptr, int size)
-{
-  FILE *file = cookie;
-  int r;
-
-  r = (int)fread(ptr, 1, (size_t)size, file);
-  if (r < size && ferror(file)) {
-    return -1;
-  }
-  if (r == 0 && feof(file)) {
-    clearerr(file);
-  }
-  return r;
-}
-
-PIC_INLINE int
-xf_file_write(void *cookie, const char *ptr, int size)
-{
-  FILE *file = cookie;
-  int r;
-
-  r = (int)fwrite(ptr, 1, (size_t)size, file);
-  if (r < size) {
-    return -1;
-  }
-  return r;
-}
-
-PIC_INLINE long
-xf_file_seek(void *cookie, long pos, int whence)
-{
-  return fseek(cookie, pos, whence);
-}
-
-PIC_INLINE int
-xf_file_flush(void *cookie)
-{
-  return fflush(cookie);
-}
-
-PIC_INLINE int
-xf_file_close(void *cookie)
-{
-  return fclose(cookie);
-}
-
-PIC_INLINE xFILE *
-xfpopen(FILE *fp)
-{
-  xFILE *file;
-
-  file = xfunopen(fp, xf_file_read, xf_file_write, xf_file_seek, xf_file_flush, xf_file_close);
-  if (! file) {
-    return NULL;
-  }
-
-  return file;
-}
-
-#define XF_FILE_VTABLE xf_file_read, xf_file_write, xf_file_seek, xf_file_flush, xf_file_close
-
-PIC_INLINE xFILE *
-xstdin_()
-{
-  static xFILE x = { -1, 0, { NULL, XF_FILE_VTABLE } };
-
-  if (! x.vtable.cookie) {
-    x.vtable.cookie = stdin;
-  }
-  return &x;
-}
-
-PIC_INLINE xFILE *
-xstdout_()
-{
-  static xFILE x = { -1, 0, { NULL, XF_FILE_VTABLE } };
-
-  if (! x.vtable.cookie) {
-    x.vtable.cookie = stdout;
-  }
-  return &x;
-}
-
-PIC_INLINE xFILE *
-xstderr_()
-{
-  static xFILE x = { -1, 0, { NULL, XF_FILE_VTABLE } };
-
-  if (! x.vtable.cookie) {
-    x.vtable.cookie = stderr;
-  }
-  return &x;
-}
-
-struct xf_membuf {
-  char *buf;
-  long pos, end, capa;
+enum _flags {
+  X_READ  = 01,
+  X_WRITE = 02,
+  X_UNBUF = 04,
+  X_EOF   = 010,
+  X_ERR   = 020,
+  X_LNBUF = 040
 };
 
-PIC_INLINE int
-xf_mem_read(void *cookie, char *ptr, int size)
-{
-  struct xf_membuf *mem;
-
-  mem = (struct xf_membuf *)cookie;
-
-  if (size > (int)(mem->end - mem->pos))
-    size = (int)(mem->end - mem->pos);
-  memcpy(ptr, mem->buf + mem->pos, size);
-  mem->pos += size;
-  return size;
-}
-
-PIC_INLINE int
-xf_mem_write(void *cookie, const char *ptr, int size)
-{
-  struct xf_membuf *mem;
-
-  mem = (struct xf_membuf *)cookie;
-
-  if (mem->pos + size >= mem->capa) {
-    mem->capa = (mem->pos + size) * 2;
-    mem->buf = realloc(mem->buf, (size_t)mem->capa);
-  }
-  memcpy(mem->buf + mem->pos, ptr, size);
-  mem->pos += size;
-  if (mem->end < mem->pos)
-    mem->end = mem->pos;
-  return size;
-}
-
-PIC_INLINE long
-xf_mem_seek(void *cookie, long pos, int whence)
-{
-  struct xf_membuf *mem;
-
-  mem = (struct xf_membuf *)cookie;
-
-  switch (whence) {
-  case SEEK_SET:
-    mem->pos = pos;
-    break;
-  case SEEK_CUR:
-    mem->pos += pos;
-    break;
-  case SEEK_END:
-    mem->pos = mem->end + pos;
-    break;
-  }
-
-  return mem->pos;
-}
-
-PIC_INLINE int
-xf_mem_flush(void *cookie)
-{
-  (void)cookie;
-
-  return 0;
-}
-
-PIC_INLINE int
-xf_mem_close(void *cookie)
-{
-  struct xf_membuf *mem;
-
-  mem = (struct xf_membuf *)cookie;
-  free(mem->buf);
-  free(mem);
-  return 0;
-}
-
-PIC_INLINE xFILE *
-xmopen()
-{
-  struct xf_membuf *mem;
-
-  mem = (struct xf_membuf *)malloc(sizeof(struct xf_membuf));
-  mem->buf = (char *)malloc(BUFSIZ);
-  mem->pos = 0;
-  mem->end = 0;
-  mem->capa = BUFSIZ;
-
-  return xfunopen(mem, xf_mem_read, xf_mem_write, xf_mem_seek, xf_mem_flush, xf_mem_close);
-}
-
-#undef XF_FILE_VTABLE
-
-PIC_INLINE xFILE *
-xfopen(const char *filename, const char *mode)
-{
-  FILE *fp;
-  xFILE *file;
-
-  fp = fopen(filename, mode);
-  if (! fp) {
-    return NULL;
-  }
-
-  file = xfpopen(fp);
-  if (! file) {
-    return NULL;
-  }
-
-  return file;
-}
-
-PIC_INLINE int
-xfclose(xFILE *file)
-{
-  int r;
-
-  r = file->vtable.close(file->vtable.cookie);
-  if (r == EOF) {
-    return -1;
-  }
-
-  free(file);
-  return 0;
-}
-
-PIC_INLINE int
-xfflush(xFILE *file)
-{
-  return file->vtable.flush(file->vtable.cookie);
-}
-
-PIC_INLINE size_t
-xfread(void *ptr, size_t block, size_t nitems, xFILE *file)
-{
-  char cbuf[256], *buf;
-  char *dst = (char *)ptr;
-  size_t i, offset;
-  int n;
-
-  if (block <= 256) {
-    buf = cbuf;
-  } else {
-    buf = malloc(block);
-  }
-
-  for (i = 0; i < nitems; ++i) {
-    offset = 0;
-    if (file->ungot != -1 && block > 0) {
-      buf[0] = (char)file->ungot;
-      offset += 1;
-      file->ungot = -1;
-    }
-    while (offset < block) {
-      n = file->vtable.read(file->vtable.cookie, buf + offset, (int)(block - offset));
-      if (n < 0) {
-        file->flags |= XF_ERR;
-        goto exit;
-      }
-      if (n == 0) {
-        file->flags |= XF_EOF;
-        goto exit;
-      }
-      offset += (unsigned)n;
-    }
-    memcpy(dst, buf, block);
-    dst += block;
-  }
-
- exit:
-
-  if (cbuf != buf) {
-    free(buf);
-  }
-  return i;
-}
-
-PIC_INLINE size_t
-xfwrite(const void *ptr, size_t block, size_t nitems, xFILE *file)
-{
-  char *dst = (char *)ptr;
-  size_t i, offset;
-  int n;
-
-  for (i = 0; i < nitems; ++i) {
-    offset = 0;
-    while (offset < block) {
-      n = file->vtable.write(file->vtable.cookie, dst + offset, (int)(block - offset));
-      if (n < 0) {
-        file->flags |= XF_ERR;
-        goto exit;
-      }
-      offset += (unsigned)n;
-    }
-    dst += block;
-  }
-
- exit:
-  return i;
-}
-
-PIC_INLINE long
-xfseek(xFILE *file, long offset, int whence)
-{
-  file->ungot = -1;
-  return file->vtable.seek(file->vtable.cookie, offset, whence);
-}
-
-PIC_INLINE long
-xftell(xFILE *file)
-{
-  return xfseek(file, 0, SEEK_CUR);
-}
-
-PIC_INLINE void
-xrewind(xFILE *file)
-{
-  xfseek(file, 0, SEEK_SET);
-}
-
-PIC_INLINE void
-xclearerr(xFILE *file)
-{
-  file->flags = 0;
-}
-
-PIC_INLINE int
-xfeof(xFILE *file)
-{
-  return file->flags & XF_EOF;
-}
-
-PIC_INLINE int
-xferror(xFILE *file)
-{
-  return file->flags & XF_ERR;
-}
-
-PIC_INLINE int
-xfgetc(xFILE *file)
-{
-  char buf[1];
-
-  xfread(buf, 1, 1, file);
-
-  if (xfeof(file) || xferror(file)) {
-    return EOF;
-  }
-
-  return buf[0];
-}
-
-PIC_INLINE int
-xgetc(xFILE *file)
-{
-  return xfgetc(file);
-}
-
-PIC_INLINE char *
-xfgets(char *str, int size, xFILE *file)
-{
-  int c = EOF, i;
-
-  for (i = 0; i < size - 1 && c != '\n'; ++i) {
-    if ((c = xfgetc(file)) == EOF) {
-      break;
-    }
-    str[i] = (char)c;
-  }
-  if (i == 0 && c == EOF) {
-    return NULL;
-  }
-  if (xferror(file)) {
-    return NULL;
-  }
-  str[i] = '\0';
-
-  return str;
-}
-
-PIC_INLINE int
-xungetc(int c, xFILE *file)
-{
-  file->ungot = c;
-  if (c != EOF) {
-    file->flags &= ~XF_EOF;
-  }
-  return c;
-}
-
-PIC_INLINE int
-xgetchar(void)
-{
-  return xfgetc(xstdin);
-}
-
-PIC_INLINE int
-xfputc(int c, xFILE *file)
-{
-  char buf[1];
-
-  buf[0] = (char)c;
-  xfwrite(buf, 1, 1, file);
-
-  if (xferror(file)) {
-    return EOF;
-  }
-  return buf[0];
-}
-
-PIC_INLINE int
-xputc(int c, xFILE *file)
-{
-  return xfputc(c, file);
-}
-
-PIC_INLINE int
-xputchar(int c)
-{
-  return xfputc(c, xstdout);
-}
-
-PIC_INLINE int
-xfputs(const char *str, xFILE *file)
-{
-  size_t len;
-
-  len = strlen(str);
-  xfwrite(str, len, 1, file);
-
-  if (xferror(file)) {
-    return EOF;
-  }
-  return 0;
-}
-
-PIC_INLINE int
-xputs(const char *s)
-{
-  return xfputs(s, xstdout);
-}
-
-PIC_INLINE int
-xprintf(const char *fmt, ...)
-{
-  va_list ap;
-  int n;
-
-  va_start(ap, fmt);
-  n = xvfprintf(xstdout, fmt, ap);
-  va_end(ap);
-  return n;
-}
-
-PIC_INLINE int
-xfprintf(xFILE *stream, const char *fmt, ...)
-{
-  va_list ap;
-  int n;
-
-  va_start(ap, fmt);
-  n = xvfprintf(stream, fmt, ap);
-  va_end(ap);
-  return n;
-}
-
-static void
-xfile_printint(xFILE *stream, long x, int base)
-{
-  static char digits[] = "0123456789abcdef";
-  char buf[20];
-  int i, neg;
-
-  neg = 0;
-  if (x < 0) {
-    neg = 1;
-    x = -x;
-  }
-
-  i = 0;
-  do {
-    buf[i++] = digits[x % base];
-  } while ((x /= base) != 0);
-
-  if (neg) {
-    buf[i++] = '-';
-  }
-
-  while (i-- > 0) {
-    xputc(buf[i], stream);
-  }
-}
-
-PIC_INLINE int
-xvfprintf(xFILE *stream, const char *fmt, va_list ap)
-{
-  const char *p;
-  char *sval;
-  int ival;
-  double dval;
-  void *vp;
-  long seekr = xftell(stream);
-
-  for (p = fmt; *p; p++) {
-    if (*p != '%') {
-      xputc(*p, stream);
-      continue;
-    }
-    switch (*++p) {
-    case 'd':
-    case 'i':
-      ival = va_arg(ap, int);
-      xfile_printint(stream, ival, 10);
-      break;
-    case 'f':
-      dval = va_arg(ap, double);
-      xfile_printint(stream, dval, 10);
-      xputc('.', stream);
-      xfile_printint(stream, fabs((dval - (int)dval) * 1e4), 10);
-      break;
-    case 's':
-      sval = va_arg(ap, char*);
-      xfputs(sval, stream);
-      break;
-    case 'p':
-      vp = va_arg(ap, void*);
-      xfputs("0x", stream);
-      xfile_printint(stream, (long)vp, 16);
-      break;
-    default:
-      xputc(*(p-1), stream);
-      break;
-    }
-  }
-  return xftell(stream) - seekr;
-}
+#define xclearerr(p) ((p)->flag &= ~(X_EOF | X_ERR))
+#define xfeof(p)     (((p)->flag & X_EOF) != 0)
+#define xferror(p)   (((p)->flag & X_ERR) != 0)
+#define xfileno(p)   ((p)->fd)
+
+#define xgetc(p)                                                \
+  ((--(p)->cnt >= 0)                                            \
+   ? (unsigned char) *(p)->ptr++                                \
+   : x_fillbuf(p))
+#define xputc(x, p)                                             \
+  ((--(p)->cnt >= 0 && !(((p)->flag & X_LNBUF) && (x) == '\n')) \
+   ? *(p)->ptr++ = (x)                                          \
+   : x_flushbuf(x, (p)))
+#define xgetchar()   xgetc(xstdin)
+#define xputchar(x)  xputc((x), xstdout)
+
+/* resource aquisition */
+xFILE *xfunopen(void *cookie, int (*read)(void *, char *, int), int (*write)(void *, const char *, int), long (*seek)(void *, long, int), int (*close)(void *));
+xFILE *xfopen(const char *, const char *);
+int xfclose(xFILE *);
+
+/* buffer management */
+int x_fillbuf(xFILE *);
+int x_flushbuf(int, xFILE *);
+int xfflush(xFILE *);
+
+/* direct IO */
+size_t xfread(void *, size_t, size_t, xFILE *);
+size_t xfwrite(const void *, size_t, size_t, xFILE *);
+
+enum {
+  XSEEK_CUR,
+  XSEEK_END,
+  XSEEK_SET
+};
+
+/* indicator positioning */
+long xfseek(xFILE *, long, int);
+long xftell(xFILE *);
+void xrewind(xFILE *);
+
+/* character IO */
+int xfputc(int, xFILE *);
+int xfgetc(xFILE *);
+int xfputs(const char *, xFILE *);
+char *xfgets(char *, int, xFILE *);
+int xputs(const char *);
+int xungetc(int, xFILE *);
+
+/* formatted I/O */
+int xprintf(const char *, ...);
+int xfprintf(xFILE *, const char *, ...);
+int xvfprintf(xFILE *, const char *, va_list);
 
 #if defined(__cplusplus)
 }
diff --git a/extlib/benz/port.c b/extlib/benz/port.c
index df6a971c..20879173 100644
--- a/extlib/benz/port.c
+++ b/extlib/benz/port.c
@@ -68,7 +68,7 @@ struct strfile {
 };
 
 static int
-strfile_read(void *cookie, char *ptr, int size)
+string_read(void *cookie, char *ptr, int size)
 {
   struct strfile *m = cookie;
 
@@ -80,7 +80,7 @@ strfile_read(void *cookie, char *ptr, int size)
 }
 
 static int
-strfile_write(void *cookie, const char *ptr, int size)
+string_write(void *cookie, const char *ptr, int size)
 {
   struct strfile *m = cookie;
 
@@ -96,18 +96,18 @@ strfile_write(void *cookie, const char *ptr, int size)
 }
 
 static long
-strfile_seek(void *cookie, long pos, int whence)
+string_seek(void *cookie, long pos, int whence)
 {
   struct strfile *m = cookie;
 
   switch (whence) {
-  case SEEK_SET:
+  case XSEEK_SET:
     m->pos = pos;
     break;
-  case SEEK_CUR:
+  case XSEEK_CUR:
     m->pos += pos;
     break;
-  case SEEK_END:
+  case XSEEK_END:
     m->pos = m->end + pos;
     break;
   }
@@ -116,15 +116,7 @@ strfile_seek(void *cookie, long pos, int whence)
 }
 
 static int
-strfile_flush(void *cookie)
-{
-  (void)cookie;
-
-  return 0;
-}
-
-static int
-strfile_close(void *cookie)
+string_close(void *cookie)
 {
   struct strfile *m = cookie;
 
@@ -134,9 +126,8 @@ strfile_close(void *cookie)
 }
 
 static xFILE *
-strfile_open(pic_state *pic)
+string_open(pic_state *pic, const char *data, size_t size)
 {
-  static const size_t size = 128;
   struct strfile *m;
   xFILE *file;
 
@@ -144,12 +135,19 @@ strfile_open(pic_state *pic)
   m->pic = pic;
   m->buf = pic_malloc(pic, size);
   m->pos = 0;
-  m->end = 0;
+  m->end = size;
   m->capa = size;
 
-  file = xfunopen(m, strfile_read, strfile_write, strfile_seek, strfile_flush, strfile_close);
+  memcpy(m->buf, data, size);
+
+  if (data != NULL) {
+    file = xfunopen(m, string_read, NULL, string_seek, string_close);
+  } else {
+    file = xfunopen(m, NULL, string_write, string_seek, string_close);
+  }
+
   if (file == NULL) {
-    strfile_close(m);
+    string_close(m);
     pic_error(pic, "could not open new output string/bytevector port", pic_nil_value());
   }
   return file;
@@ -161,14 +159,10 @@ pic_open_input_string(pic_state *pic, const char *str)
   struct pic_port *port;
 
   port = (struct pic_port *)pic_obj_alloc(pic, sizeof(struct pic_port *), PIC_TT_PORT);
-  port->file = strfile_open(pic);
+  port->file = string_open(pic, str, strlen(str));
   port->flags = PIC_PORT_IN | PIC_PORT_TEXT;
   port->status = PIC_PORT_OPEN;
 
-  xfputs(str, port->file);
-  xfflush(port->file);
-  xrewind(port->file);
-
   return port;
 }
 
@@ -178,7 +172,7 @@ pic_open_output_string(pic_state *pic)
   struct pic_port *port;
 
   port = (struct pic_port *)pic_obj_alloc(pic, sizeof(struct pic_port *), PIC_TT_PORT);
-  port->file = strfile_open(pic);
+  port->file = string_open(pic, NULL, 0);
   port->flags = PIC_PORT_OUT | PIC_PORT_TEXT;
   port->status = PIC_PORT_OPEN;
 
@@ -188,20 +182,17 @@ pic_open_output_string(pic_state *pic)
 struct pic_string *
 pic_get_output_string(pic_state *pic, struct pic_port *port)
 {
-  size_t size;
-  char *buf;
+  struct strfile *s;
+
+  if (port->file->vtable.write != string_write) {
+    pic_errorf(pic, "get-output-string: port is not made by open-output-string");
+  }
 
-  /* get endpos */
   xfflush(port->file);
-  size = (size_t)xftell(port->file);
-  xrewind(port->file);
 
-  /* copy to buf */
-  buf = (char *)pic_malloc(pic, size + 1);
-  buf[size] = 0;
-  xfread(buf, size, 1, port->file);
+  s = port->file->vtable.cookie;
 
-  return pic_make_str(pic, buf, size);
+  return pic_make_str(pic, s->buf, s->end);
 }
 
 void
@@ -417,14 +408,10 @@ pic_port_open_input_blob(pic_state *pic)
   pic_get_args(pic, "b", &blob);
 
   port = (struct pic_port *)pic_obj_alloc(pic, sizeof(struct pic_port *), PIC_TT_PORT);
-  port->file = strfile_open(pic);
+  port->file = string_open(pic, (const char *)blob->data, blob->len);
   port->flags = PIC_PORT_IN | PIC_PORT_BINARY;
   port->status = PIC_PORT_OPEN;
 
-  xfwrite(blob->data, 1, blob->len, port->file);
-  xfflush(port->file);
-  xrewind(port->file);
-
   return pic_obj_value(port);
 }
 
@@ -436,7 +423,7 @@ pic_port_open_output_bytevector(pic_state *pic)
   pic_get_args(pic, "");
 
   port = (struct pic_port *)pic_obj_alloc(pic, sizeof(struct pic_port *), PIC_TT_PORT);
-  port->file = strfile_open(pic);
+  port->file = string_open(pic, NULL, 0);
   port->flags = PIC_PORT_OUT | PIC_PORT_BINARY;
   port->status = PIC_PORT_OPEN;
 
@@ -448,20 +435,22 @@ pic_port_get_output_bytevector(pic_state *pic)
 {
   struct pic_port *port = pic_stdout(pic);
   pic_blob *blob;
-  size_t size;
+  struct strfile *s;
 
   pic_get_args(pic, "|p", &port);
 
   assert_port_profile(port, PIC_PORT_OUT | PIC_PORT_BINARY, PIC_PORT_OPEN, "get-output-bytevector");
 
-  /* get endpos */
-  xfflush(port->file);
-  size = (size_t)xftell(port->file);
-  xrewind(port->file);
+  if (port->file->vtable.write != string_write) {
+    pic_errorf(pic, "get-output-bytevector: port is not made by open-output-bytevector");
+  }
 
-  /* copy to buf */
-  blob = pic_make_blob(pic, size);
-  xfread(blob->data, 1, size, port->file);
+  xfflush(port->file);
+
+  s = port->file->vtable.cookie;
+
+  blob = pic_make_blob(pic, s->end);
+  memcpy(blob->data, s->buf, s->end);
 
   return pic_obj_value(blob);
 }
diff --git a/extlib/benz/read.c b/extlib/benz/read.c
index d2300579..ce60a995 100644
--- a/extlib/benz/read.c
+++ b/extlib/benz/read.c
@@ -856,11 +856,14 @@ pic_read(pic_state *pic, struct pic_port *port)
 pic_value
 pic_read_cstr(pic_state *pic, const char *str)
 {
-  struct pic_port *port;
+  struct pic_port *port = pic_open_input_string(pic, str);
+  pic_value form;
 
-  port = pic_open_input_string(pic, str);
+  form = pic_read(pic, port);
 
-  return pic_read(pic, port);
+  pic_close_port(pic, port);
+
+  return form;
 }
 
 static pic_value
diff --git a/extlib/benz/state.c b/extlib/benz/state.c
index efc8d2a8..571c5155 100644
--- a/extlib/benz/state.c
+++ b/extlib/benz/state.c
@@ -326,17 +326,17 @@ pic_open(int argc, char *argv[], char **envp, pic_allocf allocf)
   /* reader */
   pic->reader = pic_reader_open(pic);
 
+  /* standard I/O */
+  pic->xSTDIN = pic_make_standard_port(pic, xstdin, PIC_PORT_IN);
+  pic->xSTDOUT = pic_make_standard_port(pic, xstdout, PIC_PORT_OUT);
+  pic->xSTDERR = pic_make_standard_port(pic, xstderr, PIC_PORT_OUT);
+
   /* standard libraries */
   pic->PICRIN_BASE = pic_open_library(pic, pic_read_cstr(pic, "(picrin base)"));
   pic->PICRIN_USER = pic_open_library(pic, pic_read_cstr(pic, "(picrin user)"));
   pic->lib = pic->PICRIN_USER;
   pic->prev_lib = NULL;
 
-  /* standard I/O */
-  pic->xSTDIN = pic_make_standard_port(pic, xstdin, PIC_PORT_IN);
-  pic->xSTDOUT = pic_make_standard_port(pic, xstdout, PIC_PORT_OUT);
-  pic->xSTDERR = pic_make_standard_port(pic, xstderr, PIC_PORT_OUT);
-
   pic_gc_arena_restore(pic, ai);
 
   /* turn on GC */
diff --git a/extlib/benz/xfile.c b/extlib/benz/xfile.c
new file mode 100644
index 00000000..d09bf9bf
--- /dev/null
+++ b/extlib/benz/xfile.c
@@ -0,0 +1,472 @@
+#include "picrin.h"
+
+static int file_read(void *cookie, char *ptr, int size) {
+  FILE *file = cookie;
+  int r;
+
+  size = 1;                     /* override size */
+
+  r = (int)fread(ptr, 1, (size_t)size, file);
+  if (r < size && ferror(file)) {
+    return -1;
+  }
+  if (r == 0 && feof(file)) {
+    clearerr(file);
+  }
+  return r;
+}
+
+static int file_write(void *cookie, const char *ptr, int size) {
+  FILE *file = cookie;
+  int r;
+
+  r = (int)fwrite(ptr, 1, (size_t)size, file);
+  if (r < size) {
+    return -1;
+  }
+  fflush(cookie);
+  return r;
+}
+
+static long file_seek(void *cookie, long pos, int whence) {
+  switch (whence) {
+  case XSEEK_CUR:
+    whence = SEEK_CUR;
+    break;
+  case XSEEK_SET:
+    whence = SEEK_SET;
+    break;
+  case XSEEK_END:
+    whence = SEEK_END;
+    break;
+  }
+  return fseek(cookie, pos, whence);
+}
+
+static int file_close(void *cookie) {
+  return fclose(cookie);
+}
+
+xFILE *xfopen(const char *name, const char *mode) {
+  FILE *fp;
+
+  if ((fp = fopen(name, mode)) == NULL) {
+    return NULL;
+  }
+
+  switch (*mode) {
+  case 'r':
+    return xfunopen(fp, file_read, NULL, file_seek, file_close);
+  default:
+    return xfunopen(fp, NULL, file_write, file_seek, file_close);
+  }
+}
+
+#define FILE_VTABLE { 0, file_read, file_write, file_seek, file_close }
+
+xFILE x_iob[XOPEN_MAX] = {
+  { { 0 }, 0, NULL, NULL, FILE_VTABLE, X_READ },
+  { { 0 }, 0, NULL, NULL, FILE_VTABLE, X_WRITE | X_LNBUF },
+  { { 0 }, 0, NULL, NULL, FILE_VTABLE, X_WRITE | X_UNBUF }
+};
+
+xFILE *xfunopen(void *cookie, int (*read)(void *, char *, int), int (*write)(void *, const char *, int), long (*seek)(void *, long, int), int (*close)(void *)) {
+  xFILE *fp;
+
+  for (fp = x_iob; fp < x_iob + XOPEN_MAX; fp++)
+    if ((fp->flag & (X_READ | X_WRITE)) == 0)
+      break;  /* found free slot */
+
+  if (fp >= x_iob + XOPEN_MAX)  /* no free slots */
+    return NULL;
+
+  fp->cnt = 0;
+  fp->base = NULL;
+  fp->flag = read? X_READ : X_WRITE;
+
+  fp->vtable.cookie = cookie;
+  fp->vtable.read = read;
+  fp->vtable.write = write;
+  fp->vtable.seek = seek;
+  fp->vtable.close = close;
+
+  return fp;
+}
+
+int xfclose(xFILE *fp) {
+  xfflush(fp);
+  fp->flag = 0;
+  if (fp->base != fp->buf)
+    free(fp->base);
+  return fp->vtable.close(fp->vtable.cookie);
+}
+
+int x_fillbuf(xFILE *fp) {
+  int bufsize;
+
+  if ((fp->flag & (X_READ|X_EOF|X_ERR)) != X_READ)
+    return EOF;
+  if (fp->base == NULL) {
+    if ((fp->flag & X_UNBUF) == 0) {
+      /* no buffer yet */
+      if ((fp->base = malloc(XBUFSIZ)) == NULL) {
+        /* can't get buffer, try unbuffered */
+        fp->flag |= X_UNBUF;
+      }
+    }
+    if (fp->flag & X_UNBUF) {
+      fp->base = fp->buf;
+    }
+  }
+  bufsize = (fp->flag & X_UNBUF) ? sizeof(fp->buf) : XBUFSIZ;
+
+  fp->ptr = fp->base;
+  fp->cnt = fp->vtable.read(fp->vtable.cookie, fp->ptr, bufsize);
+
+  if (--fp->cnt < 0) {
+    if (fp->cnt == -1)
+      fp->flag |= X_EOF;
+    else
+      fp->flag |= X_ERR;
+    fp->cnt = 0;
+    return EOF;
+  }
+
+  return (unsigned char) *fp->ptr++;
+}
+
+int x_flushbuf(int x, xFILE *fp) {
+  int num_written=0, bufsize=0;
+  char c = x;
+
+  if ((fp->flag & (X_WRITE|X_EOF|X_ERR)) != X_WRITE)
+    return EOF;
+  if (fp->base == NULL && ((fp->flag & X_UNBUF) == 0)) {
+    /* no buffer yet */
+    if ((fp->base = malloc(XBUFSIZ)) == NULL) {
+      /* couldn't allocate a buffer, so try unbuffered */
+      fp->flag |= X_UNBUF;
+    } else {
+      fp->ptr = fp->base;
+      fp->cnt = XBUFSIZ - 1;
+    }
+  }
+  if (fp->flag & X_UNBUF) {
+    /* unbuffered write */
+    fp->ptr = fp->base = NULL;
+    fp->cnt = 0;
+    if (x == EOF)
+      return EOF;
+    num_written = fp->vtable.write(fp->vtable.cookie, (const char *) &c, 1);
+    bufsize = 1;
+  } else {
+    /* buffered write */
+    assert(fp->ptr);
+    if (x != EOF) {
+      *fp->ptr++ = (unsigned char) c;
+    }
+    bufsize = (int)(fp->ptr - fp->base);
+    while(bufsize - num_written > 0) {
+      int t;
+      t = fp->vtable.write(fp->vtable.cookie, fp->base + num_written, bufsize - num_written);
+      if (t < 0)
+        break;
+      num_written += t;
+    }
+
+    fp->ptr = fp->base;
+    fp->cnt = BUFSIZ - 1;
+  }
+
+  if (num_written == bufsize) {
+    return x;
+  } else {
+    fp->flag |= X_ERR;
+    return EOF;
+  }
+}
+
+int xfflush(xFILE *f) {
+  int retval;
+  int i;
+
+  retval = 0;
+  if (f == NULL) {
+    /* flush all output streams */
+    for (i = 0; i < XOPEN_MAX; i++) {
+      if ((x_iob[i].flag & X_WRITE) && (xfflush(&x_iob[i]) == -1))
+        retval = -1;
+    }
+  } else {
+    if ((f->flag & X_WRITE) == 0)
+      return -1;
+    x_flushbuf(EOF, f);
+    if (f->flag & X_ERR)
+      retval = -1;
+  }
+  return retval;
+}
+
+int xfputc(int x, xFILE *fp) {
+  return xputc(x, fp);
+}
+
+int xfgetc(xFILE *fp) {
+  return xgetc(fp);
+}
+
+int xfputs(const char *s, xFILE *stream) {
+  const char *ptr = s;
+  while(*ptr != '\0') {
+    if (xputc(*ptr, stream) == EOF)
+      return EOF;
+    ++ptr;
+  }
+  return (int)(ptr - s);
+}
+
+char *xfgets(char *s, int size, xFILE *stream) {
+  int c;
+  char *buf;
+
+  xfflush(NULL);
+
+  if (size == 0) {
+    return NULL;
+  }
+  buf = s;
+  while (--size > 0 && (c = xgetc(stream)) != EOF) {
+    if ((*buf++ = c) == '\n')
+      break;
+  }
+  *buf = '\0';
+
+  return (c == EOF && buf == s) ? NULL : s;
+}
+
+int xputs(const char *s) {
+  int i = 1;
+
+  while(*s != '\0') {
+    if (xputchar(*s++) == EOF)
+      return EOF;
+    i++;
+  }
+  if (xputchar('\n') == EOF) {
+    return EOF;
+  }
+  return i;
+}
+
+char *xgets(char *s) {
+  int c;
+  char *buf;
+
+  xfflush(NULL);
+
+  buf = s;
+  while ((c = xgetchar()) != EOF && c != '\n') {
+    *buf++ = c;
+  }
+  *buf = '\0';
+
+  return (c == EOF && buf == s) ? NULL : s;
+}
+
+int xungetc(int c, xFILE *fp) {
+  unsigned char uc = c;
+
+  if (c == EOF || fp->base == fp->ptr) {
+    return EOF;
+  }
+  fp->cnt++;
+  return *--fp->ptr = uc;
+}
+
+size_t xfread(void *ptr, size_t size, size_t count, xFILE *fp) {
+  long nbytes;
+  int c;
+
+  nbytes = size * count;
+  while (nbytes > fp->cnt) {
+    memcpy((char *)ptr, fp->ptr, fp->cnt);
+    fp->ptr += fp->cnt;
+    ptr += fp->cnt;
+    nbytes -= fp->cnt;
+    if ((c = x_fillbuf(fp)) == EOF) {
+      return (size * count - nbytes) / size;
+    } else {
+      xungetc(c, fp);
+    }
+  }
+  memcpy((char *)ptr, fp->ptr, nbytes);
+  fp->ptr += nbytes;
+  fp->cnt -= nbytes;
+  return count;
+}
+
+size_t xfwrite(const void *ptr, size_t size, size_t count, xFILE *fp) {
+  long nbytes;
+
+  nbytes = size * count;
+  while (nbytes > fp->cnt) {
+    memcpy(fp->ptr, (char *)ptr, fp->cnt);
+    fp->ptr += fp->cnt;
+    ptr += fp->cnt;
+    nbytes -= fp->cnt;
+    if (x_flushbuf(EOF, fp) == EOF) {
+      return (size * count - nbytes) / size;
+    }
+  }
+  memcpy(fp->ptr, (char *)ptr, nbytes);
+  fp->ptr += nbytes;
+  fp->cnt -= nbytes;
+  return count;
+}
+
+long xfseek(xFILE *fp, long offset, int whence) {
+  long s;
+
+  xfflush(fp);
+
+  fp->ptr = fp->base;
+  fp->cnt = 0;
+
+  if ((s = fp->vtable.seek(fp->vtable.cookie, offset, whence)) != 0)
+    return s;
+  fp->flag &= ~X_EOF;
+  return 0;
+}
+
+long xftell(xFILE *fp) {
+  return xfseek(fp, 0, XSEEK_CUR);
+}
+
+void xrewind(xFILE *fp) {
+  xfseek(fp, 0, XSEEK_SET);
+  xclearerr(fp);
+}
+
+int xprintf(const char *fmt, ...) {
+  va_list ap;
+  int n;
+
+  va_start(ap, fmt);
+  n = xvfprintf(xstdout, fmt, ap);
+  va_end(ap);
+  return n;
+}
+
+int xfprintf(xFILE *stream, const char *fmt, ...) {
+  va_list ap;
+  int n;
+
+  va_start(ap, fmt);
+  n = xvfprintf(stream, fmt, ap);
+  va_end(ap);
+  return n;
+}
+
+static int print_int(xFILE *stream, long x, int base) {
+  static char digits[] = "0123456789abcdef";
+  char buf[20];
+  int i, c, neg;
+
+  neg = 0;
+  if (x < 0) {
+    neg = 1;
+    x = -x;
+  }
+
+  i = 0;
+  do {
+    buf[i++] = digits[x % base];
+  } while ((x /= base) != 0);
+
+  if (neg) {
+    buf[i++] = '-';
+  }
+
+  c = i;
+  while (i-- > 0) {
+    xputc(buf[i], stream);
+  }
+  return c;
+}
+
+int xvfprintf(xFILE *stream, const char *fmt, va_list ap) {
+  const char *p;
+  char *sval;
+  int ival;
+#if PIC_ENABLE_FLOAT
+  double dval;
+#endif
+  void *vp;
+  int cnt = 0;
+
+  for (p = fmt; *p; p++) {
+    if (*p != '%') {
+      xputc(*p, stream);
+      cnt++;
+      continue;
+    }
+    switch (*++p) {
+    case 'd':
+    case 'i':
+      ival = va_arg(ap, int);
+      cnt += print_int(stream, ival, 10);
+      break;
+#if PIC_ENABLE_FLOAT
+    case 'f':
+      dval = va_arg(ap, double);
+      cnt += print_int(stream, dval, 10);
+      xputc('.', stream);
+      cnt++;
+      if ((ival = fabs((dval - floor(dval)) * 1e4) + 0.5) == 0) {
+        cnt += xfputs("0000", stream);
+      } else {
+        int i;
+        for (i = 0; i < 3 - (int)log10(ival); ++i) {
+          xputc('0', stream);
+          cnt++;
+        }
+        cnt += print_int(stream, ival, 10);
+      }
+      break;
+#endif
+    case 's':
+      sval = va_arg(ap, char*);
+      cnt += xfputs(sval, stream);
+      break;
+    case 'p':
+      vp = va_arg(ap, void*);
+      cnt += xfputs("0x", stream);
+      cnt += print_int(stream, (long)vp, 16);
+      break;
+    case '%':
+      xputc(*(p-1), stream);
+      cnt++;
+      break;
+    default:
+      xputc('%', stream);
+      xputc(*(p-1), stream);
+      cnt += 2;
+      break;
+    }
+  }
+  return cnt;
+}
+
+#if 0
+int main()
+{
+  char buf[256];
+
+  xgets(buf);
+
+  xprintf("%s\n", buf);
+  xprintf("hello\n");
+  xprintf("hello\n");
+  //  xfflush(0);
+}
+#endif