heatshrink Integration
Overview
Use this skill to integrate heatshrink by fixing memory budget, window/lookahead sizes, stream chunking, and decompression safety. Compression bugs often come from mismatched encoder/decoder settings or insufficient output buffers.
When To Use
Use this skill when:
- The user wants heatshrink compression/decompression on an MCU.
- The task involves compressed logs, resources, firmware chunks, OTA payloads, or serial transfer compression.
- Decompression fails, output is truncated, memory is too high, or compressed data is incompatible.
Do not use this skill for general archive formats like gzip/zip unless heatshrink is specifically involved.
First Questions
Ask for:
- Use case: logs, UI assets, firmware chunks, telemetry, or storage.
- Encoder and decoder settings: window size and lookahead.
- Streaming or one-shot mode.
- Input/output maximum sizes and RAM budget.
- Whether compressed data comes from host tools or target firmware.
- Current error or mismatch symptom.
Integration Checklist
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Match settings. Encoder and decoder window/lookahead parameters must match.
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Bound buffers. Define maximum compressed input chunk, output chunk, and decompressed size.
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Choose streaming model. Plan how input is sunk, polled, and flushed without blocking.
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Validate data integrity. Pair compression with CRC/hash when data corruption matters.
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Test worst case. Some data expands or compresses poorly; do not assume size savings.
Common Failures
- Host encoder uses different window/lookahead than MCU decoder.
- Output buffer too small and caller treats partial output as complete.
- Decompressor waits for more data because finish/flush was not called.
- Compressed firmware lacks CRC before flash write.
- Worst-case expansion exceeds allocated storage.
Verification
Before claiming heatshrink works:
- State window/lookahead, streaming mode, and buffer sizes.
- Confirm round-trip test for representative and worst-case data.
- Confirm truncated/corrupt data fails safely.
- Confirm integrity check if used for firmware or persistent assets.
Example
User:
用 heatshrink 压缩资源，设备端解压出来缺尾巴。
Agent:
- Asks for encoder settings, decoder settings, chunk sizes, and finish/flush handling.
- Checks partial-output loop and output buffer handling.
- Verifies round-trip and truncated-input behavior.