Initial import

libc/stdio/fflush.c

@@ -0,0 +1,112 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ This program is free software; you can redistribute it and/or modify         │
+│ it under the terms of the GNU General Public License as published by         │
+│ the Free Software Foundation; version 2 of the License.                      │
+│                                                                              │
+│ This program 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             │
+│ General Public License for more details.                                     │
+│                                                                              │
+│ You should have received a copy of the GNU General Public License            │
+│ along with this program; if not, write to the Free Software                  │
+│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
+│ 02110-1301 USA                                                               │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/alg/arraylist.h"
+#include "libc/bits/bits.h"
+#include "libc/bits/pushpop.h"
+#include "libc/calls/calls.h"
+#include "libc/macros.h"
+#include "libc/mem/mem.h"
+#include "libc/runtime/runtime.h"
+#include "libc/stdio/internal.h"
+#include "libc/stdio/stdio.h"
+#include "libc/sysv/consts/o.h"
+
+struct StdioFlushHandles {
+  size_t i, n;
+  FILE **p;
+};
+
+struct StdioFlush {
+  struct StdioFlushHandles handles;
+  FILE *handles_initmem[8];
+};
+
+static struct StdioFlush g_fflush;
+
+/**
+ * Blocks until data from stream buffer is written out.
+ *
+ * @param f is the stream handle
+ * @return number of bytes written or -1 on error
+ * @see fwritebuf
+ */
+int fflush(FILE *f) {
+  size_t i;
+  int res, wrote;
+  res = 0;
+  if (!f) {
+    for (i = g_fflush.handles.i; i; --i) {
+      if ((f = g_fflush.handles.p[i - 1])) {
+        if ((wrote = fflush(f)) != -1) {
+          res += wrote;
+        } else {
+          res = -1;
+          break;
+        }
+      }
+    }
+  } else if (f->fd != -1 && (f->iomode & O_WRONLY)) {
+    if (!f->state) {
+      while (f->beg != f->end) {
+        if ((wrote = fwritebuf(f)) != -1) {
+          res += wrote;
+        } else {
+          res = -1;
+          break;
+        }
+      }
+    } else if (f->state != -1) {
+      res = fseterr(f, f->state);
+    }
+  }
+  return res;
+}
+
+int fflushregister(FILE *f) {
+  size_t i;
+  struct StdioFlush *sf;
+  sf = &g_fflush;
+  sf = sf;
+  if (!sf->handles.p) {
+    sf->handles.p = &sf->handles_initmem[0];
+    pushmov(&sf->handles.n, ARRAYLEN(sf->handles_initmem));
+    __cxa_atexit(fflush, NULL, NULL);
+  }
+  for (i = sf->handles.i; i; --i) {
+    if (!sf->handles.p[i - 1]) {
+      sf->handles.p[i - 1] = f;
+      return 0;
+    }
+  }
+  return append(&sf->handles, &f);
+}
+
+void fflushunregister(FILE *f) {
+  size_t i;
+  struct StdioFlush *sf;
+  sf = &g_fflush;
+  sf = pushpop(sf);
+  for (i = sf->handles.i; i; --i) {
+    if (sf->handles.p[i - 1] == f) {
+      pushmov(&sf->handles.p[i - 1], NULL);
+      return;
+    }
+  }
+}