trace: Move the rest of common to lib/trace.

Renaming the library to something else is left to another change, as
there's already a trace lib in the wrappers dir.

1 files changed, 109 insertions, 0 deletions

diff --git a/lib/trace/trace_lookup.hpp b/lib/trace/trace_lookup.hpp
new file mode 100644
index 00000000..55655027
--- /dev/null
+++ b/lib/trace/trace_lookup.hpp
@@ -0,0 +1,109 @@
+/**************************************************************************
+ *
+ * Copyright 2011 Jose Fonseca
+ * All Rights Reserved.
+ *
+ * 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, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ **************************************************************************/
+
+/*
+ * Helper code for function name indexed lookup tables.
+ */
+
+#pragma once
+
+
+#include <assert.h>
+#include <string.h>
+
+#include <algorithm>
+#include <iostream>
+
+
+namespace trace {
+
+
+/**
+ * Generic type for (name, value) pairs.
+ */
+template< class T >
+struct Entry
+{
+    const char *name;
+    T value;
+};
+
+
+/**
+ * Function object which compare entries by name.
+ */
+template< class T >
+struct EntryCompare {
+    inline bool
+    operator() (const Entry<T> & a, const Entry<T> & b) const {
+        return strcmp(a.name, b.name) < 0;
+    }
+};
+
+
+/**
+ * Lookup the entry with the given name, .
+ *
+ * The entry table must be sorted alphabetically (the same rules used by
+ * strcmp).
+ */
+template< class T, std::size_t n >
+inline const T &
+entryLookup(const char *name, const Entry<T> (& entries)[n], const T & default_)
+{
+    typedef const Entry<T> * ConstIterator;
+
+    ConstIterator first = &entries[0];
+    ConstIterator last = &entries[n];
+
+    assert(first != last);
+
+    Entry<T> reference;
+    reference.name = name;
+
+    EntryCompare<T> compare;
+
+#ifndef NDEBUG
+    for (ConstIterator it = first; it != last; ++it) {
+        ConstIterator next = it + 1;
+        if (next != last && !compare(*it, *next)) {
+            std::cerr << "error: " << it->name << " and " << next->name << " not properly sorted\n";
+            assert(0);
+        }
+    }
+#endif
+    
+    first = std::lower_bound(first, last, reference, compare);
+  
+    if (first == last || compare(reference, *first)) {
+        return default_;
+    }
+
+    return first->value;
+}
+
+
+} /* namespace trace */
+