Make major improvements to stdio

Buffering now has optimal performance, bugs have been fixed, and some
missing apis have been introduced. This implementation is also now more
production worthy since it's less brittle now in terms of system errors.
That's going to help redbean since lua i/o is all based on stdio.

See #97

Author: jart

libc/time/usleep.c renamed to libc/calls/usleep.c

@@ -19,6 +19,7 @@
 #include "libc/alg/arraylist.internal.h"
 #include "libc/dns/dns.h"
 #include "libc/dns/hoststxt.h"
+#include "libc/errno.h"
 #include "libc/runtime/runtime.h"
 #include "libc/sock/sock.h"
 #include "libc/stdio/stdio.h"
@@ -43,28 +44,28 @@
  * @see hoststxtsort() which is the logical next step
  */
 int parsehoststxt(struct HostsTxt *ht, FILE *f) {
-  int rc;
   char *line;
   size_t linesize;
-  rc = 0;
+  struct HostsTxtEntry entry;
+  char *addr, *name, *tok, *comment;
   line = NULL;
   linesize = 0;
   while ((getline(&line, &linesize, f)) != -1) {
-    struct HostsTxtEntry entry;
-    char *addr, *name, *tok, *comment;
     if ((comment = strchr(line, '#'))) *comment = '\0';
     if ((addr = strtok_r(line, " \t\r\n\v", &tok)) &&
         inet_pton(AF_INET, addr, entry.ip) == 1) {
       entry.canon = ht->strings.i;
       while ((name = strtok_r(NULL, " \t\r\n\v", &tok))) {
         entry.name = ht->strings.i;
-        if (concat(&ht->strings, name, strnlen(name, DNS_NAME_MAX) + 1) == -1 ||
-            append(&ht->entries, &entry) == -1) {
-          rc = -1;
-        }
+        concat(&ht->strings, name, strnlen(name, DNS_NAME_MAX) + 1);
+        append(&ht->entries, &entry);
       }
     }
   }
   free(line);
-  return rc | ferror(f);
+  if (ferror(f)) {
+    errno = ferror(f);
+    return -1;
+  }
+  return 0;
 }

libc/dns/parsehoststxt.c

@@ -64,7 +64,7 @@ void vflogf_onfail(FILE *f) {
   struct stat st;
   if (IsTiny()) return;
   err = ferror(f);
-  if ((err == ENOSPC || err == EDQUOT || err == EFBIG) &&
+  if (fileno(f) != -1 && (err == ENOSPC || err == EDQUOT || err == EFBIG) &&
       (fstat(fileno(f), &st) == -1 || st.st_size > kNontrivialSize)) {
     ftruncate(fileno(f), 0);
     fseek(f, SEEK_SET, 0);
@@ -91,14 +91,15 @@ void vflogf_onfail(FILE *f) {
  */
 void(vflogf)(unsigned level, const char *file, int line, FILE *f,
              const char *fmt, va_list va) {
+  int bufmode;
   struct tm tm;
   long double t2;
   const char *prog;
   bool issamesecond;
   char buf32[32], *buf32p;
   int64_t secs, nsec, dots;
   if (!f) f = __log_file;
-  if (fileno(f) == -1) return;
+  if (!f) return;
   t2 = nowl();
   secs = t2;
   nsec = (t2 - secs) * 1e9L;
@@ -114,6 +115,8 @@ void(vflogf)(unsigned level, const char *file, int line, FILE *f,
     buf32p = "--------------------";
   }
   prog = basename(program_invocation_name);
+  bufmode = f->bufmode;
+  if (bufmode == _IOLBF) f->bufmode = _IOFBF;
   if ((fprintf)(f, "%c%s%06ld:%s:%d:%.*s:%d] ", vflogf_loglevel2char(level),
                 buf32p, rem1000000int64(div1000int64(dots)), file, line,
                 strchrnul(prog, '.') - prog, prog, getpid()) <= 0) {
@@ -122,6 +125,10 @@ void(vflogf)(unsigned level, const char *file, int line, FILE *f,
   (vfprintf)(f, fmt, va);
   va_end(va);
   fputs("\n", f);
+  if (bufmode == _IOLBF) {
+    f->bufmode = _IOLBF;
+    fflush(f);
+  }
   if (level == kLogFatal) {
     __start_fatal(file, line);
     strcpy(buf32, "unknown");

libc/log/vflogf.c

@@ -53,7 +53,7 @@ static char g_buf[512];
 static const char *g_lastsymbol;
 static struct SymbolTable *g_symbols;
 
-forceinline int GetNestingLevel(struct StackFrame *frame) {
+static noasan int GetNestingLevel(struct StackFrame *frame) {
   int nesting = -2;
   while (frame) {
     ++nesting;
@@ -69,7 +69,7 @@ forceinline int GetNestingLevel(struct StackFrame *frame) {
  * prologues of other functions. We assume those functions behave
  * according to the System Five NexGen32e ABI.
  */
-privileged void ftrace(void) {
+privileged noasan void ftrace(void) {
   size_t i, j, nesting;
   const char *symbol;
   struct StackFrame *frame;

libc/runtime/ftrace.c

@@ -35,8 +35,6 @@ FILE *fdopen(int fd, const char *mode) {
   FILE *f;
   if ((f = calloc(1, sizeof(FILE)))) {
     f->fd = fd;
-    f->reader = __freadbuf;
-    f->writer = __fwritebuf;
     f->bufmode = ischardev(fd) ? _IOLBF : _IOFBF;
     f->iomode = fopenflags(mode);
     f->size = BUFSIZ;

libc/stdio/fdopen.c

@@ -20,6 +20,7 @@
 #include "libc/bits/bits.h"
 #include "libc/bits/pushpop.h"
 #include "libc/calls/calls.h"
+#include "libc/errno.h"
 #include "libc/macros.internal.h"
 #include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
@@ -36,28 +37,26 @@
  */
 int fflush(FILE *f) {
   size_t i;
-  int rc;
-  rc = 0;
+  ssize_t rc;
   if (!f) {
     for (i = __fflush.handles.i; i; --i) {
       if ((f = __fflush.handles.p[i - 1])) {
-        if (fflush(f) == -1) {
-          rc = -1;
-          break;
-        }
+        if (fflush(f) == -1) return -1;
       }
     }
   } else if (f->fd != -1) {
-    while (f->beg && !f->end) {
-      if (__fwritebuf(f) == -1) {
-        rc = -1;
-        break;
+    while (f->beg && !f->end && (f->iomode & O_ACCMODE) != O_RDONLY) {
+      if ((rc = write(f->fd, f->buf, f->beg)) == -1) {
+        f->state = errno;
+        return -1;
       }
+      if (rc != f->beg) abort();
+      f->beg = 0;
     }
   } else if (f->beg && f->beg < f->size) {
     f->buf[f->beg] = 0;
   }
-  return rc;
+  return 0;
 }
 
 textstartup int __fflush_register(FILE *f) {

libc/stdio/fflush.c

@@ -16,22 +16,18 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/stdio/internal.h"
 #include "libc/stdio/stdio.h"
 
-static noinline int __fgetc(FILE *f) {
-  if (!f->reader) return __fseteof(f);
-  if (f->reader(f) == -1) return -1;
-  return f->buf[f->beg++];
-}
-
 /**
- * Reads uint8_t from stream.
+ * Reads byte from stream.
+ * @return byte in range 0..255, or -1 w/ errno
  */
 int fgetc(FILE *f) {
+  unsigned char b;
   if (f->beg < f->end) {
-    return f->buf[f->beg++];
+    return f->buf[f->beg++] & 0xff;
   } else {
-    return __fgetc(f);
+    if (!fread(&b, 1, 1, f)) return -1;
+    return b;
   }
 }

libc/stdio/fgetc.c

@@ -17,16 +17,35 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/stdio/stdio.h"
+#include "libc/str/thompike.h"
 #include "libc/str/tpdecodecb.internal.h"
 
 /**
  * Reads UTF-8 character from stream.
- *
  * @return wide character or -1 on EOF or error
  */
 wint_t fgetwc(FILE *f) {
-  wint_t res;
-  res = -1;
-  tpdecodecb(&res, fgetc(f), (void *)fgetc, f);
-  return res;
+  int c, n;
+  wint_t b, x, y;
+  if (f->beg < f->end) {
+    b = f->buf[f->beg++] & 0xff;
+  } else if ((c = fgetc(f)) != -1) {
+    b = c;
+  } else {
+    return -1;
+  }
+  if (b < 0300) return b;
+  n = ThomPikeLen(b);
+  x = ThomPikeByte(b);
+  while (--n) {
+    if ((c = fgetc(f)) == -1) return -1;
+    y = c;
+    if (ThomPikeCont(y)) {
+      x = ThomPikeMerge(x, y);
+    } else {
+      ungetc(y, f);
+      return b;
+    }
+  }
+  return x;
 }

libc/stdio/fgetwc.c

@@ -24,10 +24,10 @@
  * Reads UTF-8 content from stream into UTF-32 buffer.
  */
 wchar_t *fgetws(wchar_t *s, int size, FILE *f) {
+  wint_t c;
   wchar_t *p = s;
   if (size > 0) {
     while (--size > 0) {
-      wint_t c;
       if ((c = fgetwc(f)) == -1) {
         if (ferror(f) == EINTR) continue;
         break;

libc/stdio/fgetws.c

@@ -32,39 +32,33 @@ FILE *fmemopen(void *buf, size_t size, const char *mode) {
   FILE *f;
   char *p;
   unsigned flags;
-
   if (size && size > 0x7ffff000) {
     einval();
     return NULL;
   }
-
   if (!(f = calloc(1, sizeof(FILE)))) {
     return NULL;
   }
-
-  if (!buf) {
+  if (buf) {
+    f->nofree = true;
+  } else {
     if (!size) size = BUFSIZ;
     if (!(buf = calloc(1, size))) {
       free(f);
       return NULL;
     }
-  } else {
-    f->nofree = true;
   }
-
   f->fd = -1;
   f->buf = buf;
-  f->size = size;
   f->end = size;
+  f->size = size;
   f->iomode = fopenflags(mode);
-
   if (f->iomode & O_APPEND) {
     if ((p = memchr(buf, '\0', size))) {
       f->beg = p - (char *)buf;
     } else {
       f->beg = f->end;
     }
   }
-
   return f;
 }