Flamegraph Analysis

[ReagentX]

Changes:

• Attachment::from_row()
  • Double attachment query performance (+3% overall)
• Message::get_replies()
  • No changes needed
• TypedStreamReader::parse()
• Message::from_row()
  • Set SQLITE_OPEN_NOMUTEX (+40% overall)

Original flamegraph (calls in pink were removed or improved):

Final flamegraph:

[ReagentX]

Attachment::from_row() can benefit from selecting specific columns, falling back to using * if the column names are not present in the provided table.

Before:

After:

[ReagentX]

Message::get_replies() is already quite fast on a per-call basis: Status: OK. Duration: 0.000900s. Likely, we just make this query a lot because there are a lot of threaded messages.

[ReagentX]

Message::from_row() performs a lot of allocations, but it is designed to own all of the data from a row, and there are a lot of rows to go through. The query is fast and we already use a cursor to lazily evaluate it.

However, looking at the call stack closely, we can see that we are using some very slow mutex operations on the SQLite side:

This can be resolved by setting SQLITE_OPEN_NOMUTEX, which leads to a massive 40% speedup:

[ReagentX]

Removing calls to TypedStreamReader::parse() leads to about a 30% speedup, but loses a ton of important data stored in the TypedStream blobs. Most of the time is spent in read_types(), which performs a lot of allocations and copies that can likely be optimized with some careful lifetime management.