First release of open-appsec source code

components/security_apps/waap/waap_clib/KeyStack.h

@@ -0,0 +1,81 @@
+// Copyright (C) 2022 Check Point Software Technologies Ltd. All rights reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef __KEYSTACK_H__0a8039e6
+#define __KEYSTACK_H__0a8039e6
+
+#include <stddef.h>
+#include <string>
+#include <vector>
+
+// Represent string (key) that is concatenation of  substrings (subkeys) separated by '.' character.
+// Mostly emulates API of C++ std::string class, with addition of push() and pop() methods
+// that append individual subkey and delete last subkey from the string efficiently.
+class KeyStack {
+public:
+    KeyStack(const char *name);
+    void push(const char *subkey, size_t subkeySize, bool countDepth=true);
+    void pop(const char* log, bool countDepth=true);
+    bool empty() const { return m_key.empty(); }
+    void clear() { m_key.clear(); m_stack.clear(); }
+    size_t depth() const { return m_nameDepth; }
+    size_t size() const {
+        return str().size();
+    }
+    const char *c_str() const {
+        // If pushed none - return empty string.
+        // If pushed once - still return empty string (the once-pushed subkey will only be returned
+        //                  by the first() method.
+        // If pushed twice or more - return all subkeys starting from the second one.
+        // Also, even if pushed 2 or more times, but pushed empty strings as subkeys,
+        // then it could happen that m_key is still empty, in which case we should still return empty string.
+        if (m_stack.size() <= 1 || m_stack[1] + 1 >= m_key.size()) {
+            return "";
+        }
+
+        return m_key.c_str() + m_stack[1] + 1;
+    }
+    const std::string str() const {
+        // If pushed none - return empty string.
+        // If pushed once - still return empty string (the once-pushed subkey will only be returned
+        //                  by the first() method.
+        // If pushed twice or more - return all subkeys starting from the second one.
+        // Also, even if pushed 2 or more times, but pushed empty strings as subkeys,
+        // then it could happen that m_key is still empty, in which case we should still return empty string.
+        if (m_stack.size() <= 1 || m_stack[1] + 1 >= m_key.size()) {
+            return "";
+        }
+
+        return m_key.substr(m_stack[1] + 1);
+    }
+    const std::string first() const {
+        if (m_stack.size() == 0) {
+            return "";
+        }
+        else if (m_stack.size() == 1) {
+            return m_key;
+        }
+        else {
+            // m_stack.size() > 1, so m_stack[1] is valid
+            return m_key.substr(0, m_stack[1]);
+        }
+    }
+private:
+    const char *m_name;
+    std::string m_key;
+    std::vector<size_t> m_stack;    // position of individual key name starts in m_key,
+                                    // used to backtrack 1 key at a time.
+    int m_nameDepth;
+};
+
+#endif // __KEYSTACK_H__0a8039e6