Security-57031.1.35.tar.gz

[apple/security.git] / Security / libsecurity_utilities / lib / fdsel.cpp

diff --git a/Security/libsecurity_utilities/lib/fdsel.cpp b/Security/libsecurity_utilities/lib/fdsel.cpp
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+++ b/Security/libsecurity_utilities/lib/fdsel.cpp
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+/*
+ * Copyright (c) 2000-2001,2004,2011,2014 Apple Inc. All Rights Reserved.
+ * 
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+//
+// fdsel - select-style file descriptor set management
+//
+#include "fdsel.h"
+
+
+namespace Security {
+namespace UnixPlusPlus {
+
+
+//
+// Throw the bitvectors away on destruction
+// 
+FDSet::~FDSet()
+{
+    delete mBits;
+    delete mUseBits;
+}
+
+
+//
+// Given the old and desired new sizes (in fd_mask words), grow
+// the bitvectors. New storage is zero filled. Note that we preserve
+// the mUseBits vector, so this is safe to do during a post-select scan.
+// This function cannot shrink the bitmaps.
+//
+void FDSet::grow(int oldWords, int newWords)
+{
+    assert(oldWords < newWords);
+    grow(mBits, oldWords, newWords);
+    grow(mUseBits, oldWords, newWords);
+}
+
+void FDSet::grow(fd_mask * &bits, int oldWords, int newWords)
+{
+    fd_mask *newBits = new fd_mask[newWords];
+    memcpy(newBits, bits, oldWords * sizeof(fd_mask));
+    memset(newBits + oldWords, 0, (newWords - oldWords) * sizeof(fd_mask));
+    delete [] bits;
+    bits = newBits;
+}
+
+
+//
+// Set or clear a single bit in the map.
+// No check for overflow is perfomed.
+//
+void FDSet::set(int fd, bool on)
+{
+    if (on) {
+        FD_SET(fd, (fd_set *)mBits);
+    } else {
+        FD_CLR(fd, (fd_set *)mBits);
+        FD_CLR(fd, (fd_set *)mUseBits);
+    }
+}
+
+
+//
+// Copy only the first words fd_mask words from mBits to mUseBits
+// and return that for select(2) use.
+//
+fd_set *FDSet::make(int words)
+{
+    //@@@ if empty -> return NULL (but check caller for [] use)
+    memcpy(mUseBits, mBits, words * sizeof(fd_mask));
+    return (fd_set *)mUseBits;
+}
+
+
+}      // end namespace IPPlusPlus
+}      // end namespace Security