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17 
18 /**
19  * @brief This module provides a set of diagnostic tracing utilities.
20  *
21  * Overview
22  * ========
23  *
24  * The built-in diagnostic trace tool generates a hierarchical JSON tree structure. The tree
25  * hierarchy contains three levels:
26  *
27  *    - block
28  *        - pass
29  *           - candidate
30  *
31  * One block node exists for each compressed block in the image. One pass node exists for each major
32  * pass (N partition, M planes, O components) applied to a block. One candidate node exists for each
33  * encoding candidate trialed for a pass.
34  *
35  * Each node contains both the hierarchy but also a number of attributes which explain the behavior.
36  * For example, the block node contains the block coordinates in the image, the pass explains the
37  * pass configuration, and the candidate will explain the candidate encoding such as weight
38  * decimation, refinement error, etc.
39  *
40  * Trace Nodes are designed as scope-managed C++ objects with stack-like push/pop behavior.
41  * Constructing a trace node on the stack will automatically add it to the current node as a child,
42  * and then make it the current node. Destroying the current node will pop the stack and set the
43  * parent to the current node. This provides a robust mechanism for ensuring reliable nesting in the
44  * tree structure.
45  *
46  * A set of utility macros are provided to add attribute annotations to the current trace node.
47  *
48  * Usage
49  * =====
50  *
51  * Create Trace Nodes on the stack using the @c TRACE_NODE() macro. This will compile-out completely
52  * in builds with diagnostics disabled.
53  *
54  * Add annotations to the current trace node using the @c trace_add_data() macro. This will
55  * similarly compile out completely in builds with diagnostics disabled.
56  *
57  * If you need to add additional code to support diagnostics-only behavior wrap
58  * it in preprocessor guards:
59  *
60  *     #if defined(ASTCENC_DIAGNOSTICS)
61  *     #endif
62  */
63 
64 #ifndef ASTCENC_DIAGNOSTIC_TRACE_INCLUDED
65 #define ASTCENC_DIAGNOSTIC_TRACE_INCLUDED
66 
67 #if defined(ASTCENC_DIAGNOSTICS)
68 
69 #include <iostream>
70 #include <fstream>
71 #include <vector>
72 
73 /**
74  * @brief Class representing a single node in the trace hierarchy.
75  */
76 class TraceNode
77 {
78 public:
79 	/**
80 	 * @brief Construct a new node.
81 	 *
82 	 * Constructing a node will push to the the top of the stack, automatically making it a child of
83 	 * the current node, and then setting it to become the current node.
84 	 *
85 	 * @param format   The format template for the node name.
86 	 * @param ...      The format parameters.
87 	 */
88 	TraceNode(const char* format, ...);
89 
90 	/**
91 	 * @brief Add an attribute to this node.
92 	 *
93 	 * Note that no quoting is applied to the @c value, so if quoting is needed it must be done by
94 	 * the caller.
95 	 *
96 	 * @param type    The type of the attribute.
97 	 * @param key     The key of the attribute.
98 	 * @param value   The value of the attribute.
99 	 */
100 	void add_attrib(std::string type, std::string key, std::string value);
101 
102 	/**
103 	 * @brief Destroy this node.
104 	 *
105 	 * Destroying a node will pop it from the top of the stack, making its parent the current node.
106 	 * It is invalid behavior to destroy a node that is not the current node; usage must conform to
107 	 * stack push-pop semantics.
108 	 */
109 	~TraceNode();
110 
111 	/**
112 	 * @brief The number of attributes and child nodes in this node.
113 	 */
114 	unsigned int m_attrib_count { 0 };
115 };
116 
117 /**
118  * @brief Class representing the trace log file being written.
119  */
120 class TraceLog
121 {
122 public:
123 	/**
124 	 * @brief Create a new trace log.
125 	 *
126 	 * The trace log is global; there can be only one at a time.
127 	 *
128 	 * @param file_name   The name of the file to write.
129 	 */
130 	TraceLog(const char* file_name);
131 
132 	/**
133 	 * @brief Detroy the trace log.
134 	 *
135 	 * Trace logs MUST be cleanly destroyed to ensure the file gets written.
136 	 */
137 	~TraceLog();
138 
139 	/**
140 	 * @brief Get the current child node.
141 	 *
142 	 * @return The current leaf node.
143 	 */
144 	TraceNode* get_current_leaf();
145 
146 	/**
147 	 * @brief Get the stack depth of the current child node.
148 	 *
149 	 * @return The current leaf node stack depth.
150 	 */
151 	size_t get_depth();
152 
153 	/**
154 	 * @brief The file stream to write to.
155 	 */
156 	std::ofstream m_file;
157 
158 	/**
159 	 * @brief The stack of nodes (newest at the back).
160 	 */
161 	std::vector<TraceNode*> m_stack;
162 
163 private:
164 	/**
165 	 * @brief The root node in the JSON file.
166 	 */
167 	TraceNode* m_root;
168 };
169 
170 /**
171  * @brief Utility macro to create a trace node on the stack.
172  *
173  * @param name     The variable name to use.
174  * @param ...      The name template and format parameters.
175  */
176 #define TRACE_NODE(name, ...) TraceNode name(__VA_ARGS__);
177 
178 /**
179  * @brief Add a string annotation to the current node.
180  *
181  * @param key      The name of the attribute.
182  * @param format   The format template for the attribute value.
183  * @param ...      The format parameters.
184  */
185 void trace_add_data(const char* key, const char* format, ...);
186 
187 /**
188  * @brief Add a float annotation to the current node.
189  *
190  * @param key     The name of the attribute.
191  * @param value   The value of the attribute.
192  */
193 void trace_add_data(const char* key, float value);
194 
195 /**
196  * @brief Add an integer annotation to the current node.
197  *
198  * @param key     The name of the attribute.
199  * @param value   The value of the attribute.
200  */
201 void trace_add_data(const char* key, int value);
202 
203 /**
204  * @brief Add an unsigned integer annotation to the current node.
205  *
206  * @param key     The name of the attribute.
207  * @param value   The value of the attribute.
208  */
209 void trace_add_data(const char* key, unsigned int value);
210 
211 #else
212 
213 #define TRACE_NODE(name, ...)
214 
215 #define trace_add_data(...)
216 
217 #endif
218 
219 #endif
220