benchmark silo added

[c11concurrency-benchmarks.git] / silo / masstree / file.cc

diff --git a/silo/masstree/file.cc b/silo/masstree/file.cc
new file mode 100644 (file)
index 0000000..7586878
--- /dev/null
+++ b/silo/masstree/file.cc
@@ -0,0 +1,92 @@
+/* Masstree
+ * Eddie Kohler, Yandong Mao, Robert Morris
+ * Copyright (c) 2012-2014 President and Fellows of Harvard College
+ * Copyright (c) 2012-2014 Massachusetts Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, subject to the conditions
+ * listed in the Masstree LICENSE file. These conditions include: you must
+ * preserve this copyright notice, and you cannot mention the copyright
+ * holders in advertising related to the Software without their permission.
+ * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
+ * notice is a summary of the Masstree LICENSE file; the license in that file
+ * is legally binding.
+ */
+#include "file.hh"
+#include "straccum.hh"
+#include <fcntl.h>
+#include <stdio.h>
+
+lcdf::String read_file_contents(int fd) {
+    lcdf::StringAccum sa;
+    while (1) {
+        char *buf = sa.reserve(4096);
+        if (!buf) {
+            errno = ENOMEM;
+            return lcdf::String();
+        }
+
+        ssize_t x = read(fd, buf, 4096);
+        if (x != -1 && x != 0)
+            sa.adjust_length(x);
+        else if (x == 0)
+            break;
+        else if (errno != EINTR)
+            return lcdf::String();
+    }
+
+    errno = 0;
+    return sa.take_string();
+}
+
+lcdf::String read_file_contents(const char *filename) {
+    int fd = open(filename, O_RDONLY);
+    if (fd == -1)
+        return lcdf::String();
+
+    lcdf::String text = read_file_contents(fd);
+
+    if (text.empty() && errno) {
+        int saved_errno = errno;
+        close(fd);
+        errno = saved_errno;
+    }
+    return text;
+}
+
+int sync_write_file_contents(const char *filename, const lcdf::String &contents,
+                             mode_t mode)
+{
+    int fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, mode);
+    if (fd == -1)
+        return -1;
+
+    ssize_t x = safe_write(fd, contents.data(), contents.length());
+    if (x != contents.length()) {
+    error:
+        close(fd);
+        return -1;
+    }
+
+    int r = fsync(fd);
+    if (r != 0)
+        goto error;
+
+    r = close(fd);
+    if (r != 0)
+        goto error;
+
+    return 0;
+}
+
+int atomic_write_file_contents(const char *filename, const lcdf::String &contents,
+                               mode_t mode)
+{
+    lcdf::String tmp_filename = lcdf::String(filename) + ".tmp";
+    int r = sync_write_file_contents(tmp_filename.c_str(), contents, mode);
+    if (r != 0)
+        return -1;
+
+    return rename(tmp_filename.c_str(), filename);
+}