perf: cache command string and add zero-allocation integer parsing#189
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tonivade merged 3 commits intotonivade:masterfrom Mar 30, 2026
Merged
perf: cache command string and add zero-allocation integer parsing#189tonivade merged 3 commits intotonivade:masterfrom
tonivade merged 3 commits intotonivade:masterfrom
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March 23, 2026 09:49
Two related allocation-reduction optimizations: 1. Cache the result of getCommand() in DefaultRequest to avoid repeated SafeString.toString() conversions. The command name is immutable per request, so lazy-init caching is safe. 2. Add SafeString.parseIntAfterPrefix() that parses the integer value directly from the underlying ByteBuffer, skipping the first byte (the RESP type prefix). This replaces the pattern of substring(1) + Integer.parseInt() in RedisParser, eliminating a temporary String allocation per parsed RESP header. Made-with: Cursor
- SafeStringTest: verify parseIntAfterPrefix() for positive, negative, zero, and large integers with various RESP prefixes - DefaultRequestTest: verify getCommand() returns same cached instance across calls, and isExit() correctly uses the cached value Made-with: Cursor
tonivade
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Mar 30, 2026
| for (int i = start; i < lim; i++) { | ||
| byte b = buffer.get(i); | ||
| if (b < '0' || b > '9') { | ||
| break; |
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this should throw a NumberFormatException, right? also this case should be verified in tests
src/main/java/com/github/tonivade/resp/command/DefaultRequest.java
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Made-with: Cursor
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Summary
DefaultRequestto avoid repeatedSafeString.toString()conversions.SafeString.parseIntAfterPrefix()for zero-allocation integer parsing of RESP protocol headers, replacing thesubstring(1)+Integer.parseInt()pattern inRedisParser.Motivation
In the hot path of command processing:
DefaultRequest.getCommand()is called multiple times per request (dispatch, logging, exit check). Each call previously allocated a new String viaSafeString.toString().RedisParserparses every RESP frame header (*3,$5,:1) by first creating a substring (allocation), then parsing the integer.parseIntAfterPrefix()reads digits directly from the ByteBuffer — zero allocation.Changes
DefaultRequest.java: lazy-cachecommandStringfield; reuse inisExit()SafeString.java: newparseIntAfterPrefix()method — parses integer from buffer position+1, handles negative numbersRedisParser.java: useparseIntAfterPrefix()inparseToken(),parseIntegerToken(), andparseStringToken()Test plan