Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/sal/osl/unx/readwrite_helper.cxx b/sal/osl/unx/readwrite_helper.cxx
new file mode 100644
index 000000000..49c44c2c0
--- /dev/null
+++ b/sal/osl/unx/readwrite_helper.cxx
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <sal/config.h>
+
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <limits>
+
+#include "readwrite_helper.hxx"
+
+#include "system.hxx"
+
+namespace {
+
+std::size_t cap_ssize_t(std::size_t value) {
+    return std::min(value, std::size_t(std::numeric_limits<ssize_t>::max()));
+}
+
+}
+
+bool safeWrite(int fd, void* data, std::size_t dataSize)
+{
+    auto nToWrite = dataSize;
+    unsigned char* dataToWrite = static_cast<unsigned char *>(data);
+
+    while ( nToWrite ) {
+        auto nWritten = write(fd, dataToWrite, cap_ssize_t(nToWrite));
+        if ( nWritten < 0 ) {
+            if ( errno == EINTR )
+                continue;
+
+            return false;
+
+        }
+
+        assert(nWritten > 0);
+        nToWrite -= nWritten;
+        dataToWrite += nWritten;
+    }
+
+    return true;
+}
+
+bool safeRead( int fd, void* buffer, std::size_t count )
+{
+    auto nToRead = count;
+    unsigned char* bufferForReading = static_cast<unsigned char *>(buffer);
+
+    while ( nToRead ) {
+        auto nRead = read(fd, bufferForReading, cap_ssize_t(nToRead));
+        if ( nRead < 0 ) {
+            // We were interrupted before reading, retry.
+            if (errno == EINTR)
+                continue;
+
+            return false;
+        }
+
+        // If we reach the EOF, we consider this a partial transfer and thus
+        // an error.
+        if ( nRead == 0 )
+            return false;
+
+        nToRead -= nRead;
+        bufferForReading += nRead;
+    }
+
+    return true;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */