Doca Compress

DOCA Compress

Where to start: This skill assumes DOCA is already installed and the user is doing hands-on Compress work (bulk DEFLATE compression or decompression) on a BlueField / ConnectX / host with DOCA. Open TASKS.md if the user wants to do something (configure / build / modify / run / test / debug); open CAPABILITIES.md when the question is what can DOCA Compress express on this version. If the user has not installed DOCA yet, route to doca-setup first. If the user is asking "should I even offload this compression to the accelerator?", the size-threshold path-selection rule in CAPABILITIES.md ## Capabilities and modes is the first stop — bulk compress is the canonical fit, tiny one-shot is not.

Example questions this skill answers well

The CLASSES of DOCA Compress questions this skill is built to answer, each with one worked example. The agent should treat the class as the load-bearing piece — the worked example is a single instance.

• "Should I offload this compression to DOCA Compress, or just zlib/zstd on the CPU?" — worked example: "I am compressing a 4 MiB log buffer before writing it to storage; is doca-compress worth the setup vs zlib on the CPU?". Answered by the size-threshold path-selection rule in CAPABILITIES.md ## Capabilities and modes
  • the "when NOT to use doca-compress" bullets in CAPABILITIES.md ## Safety policy.
• "Does my device support the compress (or decompress) task I want, and how big a buffer can it move per submission?" — worked example: "is doca_compress_task_compress_deflate on this BlueField, and what is the max source size per task?". Answered by the per-task capability-query rule (doca_compress_cap_task_compress_deflate_is_supported, _decompress_deflate_is_supported, the matching _get_max_buf_size queries) in CAPABILITIES.md ## Capabilities and modes
  • the discovery step in TASKS.md ## configure.
• "I just need to decompress incoming network data — is that a valid standalone use of doca-compress?" — worked example: "my client receives DEFLATE-compressed payloads and never produces any compressed output of its own". Answered by the "decompression-only" note in CAPABILITIES.md ## Capabilities and modes task-type table + the per-task configuration matrix in TASKS.md ## configure step 5.
• "What permissions does the source / destination mmap need?" — worked example: "my doca_compress_task_compress_deflate returns DOCA_ERROR_NOT_PERMITTED". Answered by the permission matrix in CAPABILITIES.md ## Safety policy
  • the mmap-set-permissions checklist in TASKS.md ## test.
• "Is this DOCA Compress API available on my installed DOCA version?" — worked example: "is doca_compress_task_decompress_deflate in the DOCA I have installed?". Answered by the version-compatibility overlay in CAPABILITIES.md ## Version compatibility, which cross-links the canonical detection chain in doca-version and adds the Compress-specific "discover per-task support, do not assume" bullets.
• "What does this DOCA_ERROR_* from a Compress call mean and which layer caused it?" — worked example: "DOCA_ERROR_INVALID_VALUE on doca_compress_task_compress_deflate_alloc_init". Answered by the Compress overlay on the cross-library taxonomy in CAPABILITIES.md ## Error taxonomy
  • the layered ladder in TASKS.md ## debug that escalates to doca-debug.

Audience

This skill serves external developers building applications that consume the DOCA Compress library — i.e., users whose code calls doca_compress_* (directly in C/C++, or through FFI/bindings from another language) to offload bulk DEFLATE compression or decompression onto a BlueField DPU or ConnectX accelerator. It is not for NVIDIA developers contributing to DOCA Compress itself.

Language scope. DOCA Compress ships as a C library with pkg-config module name doca-compress. The shipped samples are written in C. C and C++ consumers are the canonical case and the worked examples in TASKS.md assume that path. Other-language consumers (Rust, Go, Python, …) consume the same *.so through FFI or language-specific bindings; the skill's contribution in that case is to keep the lifecycle, capability-discovery, permission, error-taxonomy, and compress-vs-decompress guidance language-neutral, and to route the agent to the public C ABI as the authoritative surface that any wrapper will eventually call.

When to load this skill

Load this skill when the user is doing hands-on DOCA Compress work, in any language. Concretely:

• Initializing a doca_compress context on a doca_dev and configuring at least one task type (doca_compress_task_compress_deflate and/or doca_compress_task_decompress_deflate) before doca_ctx_start().
• Choosing between the compress task and the decompress task for the user's data flow. The two task types are independent: a consumer that only decompresses inbound DEFLATE payloads is a valid shape and does not need to enable the compress task.
• Setting permissions on doca_mmap correctly for the source buffer (DOCA_ACCESS_FLAG_LOCAL_READ_ONLY at minimum) and the destination buffer (DOCA_ACCESS_FLAG_LOCAL_READ_WRITE).
• Sizing the source buffer against the per-task doca_compress_cap_task_*_get_max_buf_size(devinfo) ceiling and the destination buffer against the worst-case output size the algorithm can produce on this input.
• Checking which task types this device's accelerator advertises via doca_compress_cap_task_compress_deflate_is_supported and doca_compress_cap_task_decompress_deflate_is_supported against the active doca_devinfo.
• Validating against a round-trip (compress → decompress, or decompress → compare against a known DEFLATE-encoded fixture) before pushing bulk input through the accelerator.
• Deciding whether to offload at all — the size-threshold rule in CAPABILITIES.md ## Capabilities and modes says doca-compress is the right answer only for bulk inputs (rule of thumb: ≥ a few KiB); below that, CPU compression beats the DMA-to-accelerator round-trip.
• Debugging a DOCA_ERROR_* returned from a Compress call (lifecycle vs. buffer-sizing vs. permission vs. unsupported-task) and the task-completion event on the progress engine.
• Designing or extending non-C bindings (Rust, Go, Python, …) that wrap the Compress C ABI — for the lifecycle, permission, capability, and compress-vs-decompress rules the wrapper must honor.

Do not load this skill for general DOCA orientation, install of DOCA itself, non-DEFLATE compression libraries on CPU (use zlib / zstd / similar), or other DOCA libraries. For those, use doca-public-knowledge-map.