Update README.md

README.md

@@ -30,6 +30,16 @@ $ go tool pprof -http=:5079 ./grf.out
 
 The opened HTML page displays the reference distribution of the heap memory. You can choose to view the "inuse space" or "inuse objects".
 
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+<img width="1920" alt="image" src="https://github.com/cloudwego/goref/assets/24311963/a9fe0294-fe58-456a-a9d5-a8cb25049bff">
+<br />
+
+View flame graph of inuse objects:
+
+
+<img width="1916" alt="image" src="https://github.com/cloudwego/goref/assets/24311963/24e80f51-3af3-4405-8f71-57e51c42c7ed">
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+
 It also supports analyzing core files, e.g.
 
 ```
@@ -39,6 +49,17 @@ successfully output to `grf.out`
 
 > Supported go version for executable file: go1.17 ~ go1.22.
 
+
+## Principle
+The main steps of Goref reference analysis are as follows:
+
+1. Based on Delve, implement the functionality to attach processes and parse core files to achieve memory reading of the process to be analyzed.
+2. Parse the goroutine stack, data/bss segments, and heap span address space ranges, as well as gcmask, from the memory of the process to be analyzed, and build an index in the tool's runtime memory.
+3. Read DWARF Entries from the process executable file, parse the type descriptions of global variables and goroutine local variables, and calculate the actual memory addresses using Location expressions.
+4. Starting from the root objects obtained from step 3, prioritize object retrieval based on their DWARF types, determining the reference paths of all objects whose types can be determined.
+5. Search for gcmask and perform a second search for any objects that were not accessed during the DWARF retrieval in step 4, recording the found objects on the reference paths of known types.
+6. Record the number of objects and memory space occupied by all reference chains in the pprof file buffer, and then flush it to a file. In this way, we'll obtain a complete flame graph of the reference chains.
+
 ## Credit
 
-Thanks to [Delve](https://github.com/go-delve/delve) for providing powerful golang debugger.
+Thanks to [Delve](https://github.com/go-delve/delve) for providing powerful golang debugger.