This change introduces an iterator for the history index in the pathdb.
It provides sequential access to historical entries, enabling efficient
scanning and future features built on top of historical state traversal.
In this PR, the database batch for writing the history index data is
pre-allocated.
It's observed that database batch repeatedly grows the size of the
mega-batch,
causing significant memory allocation pressure. This approach can
effectively
mitigate the overhead.
`binary.AppendUvarint` offers better performance than using append
directly, because it avoids unnecessary memory allocation and copying.
In our case, it can increase the performance by +35.8% for the
`blockWriter.append` function:
```
benchmark old ns/op new ns/op delta
BenchmarkBlockWriterAppend-8 5.97 3.83 -35.80%
```
---------
Signed-off-by: jsvisa <delweng@gmail.com>
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
The implementation of `parseIndexBlock` used a reverse loop with slice
appends to build the restart points, which was less cache-friendly and
involved unnecessary allocations and operations. In this PR we change
the implementation to read and validate the restart points in one single
forward loop.
Here is the benchmark test:
```bash
go test -benchmem -bench=BenchmarkParseIndexBlock ./triedb/pathdb/
```
The result as below:
```
benchmark old ns/op new ns/op delta
BenchmarkParseIndexBlock-8 52.9 37.5 -29.05%
```
about 29% improvements
---------
Signed-off-by: jsvisa <delweng@gmail.com>
