# ZJX 1.21 STREAMWALL Source Note Date: 2026-08-30 Publisher: Greyforge Labs Canonical Chronicle: https://greyforge.tech/chronicles/zjx-1-21-streamwall-bounded-memory Implementation revision: sealed inside the private release evidence packet Release evidence packet: 103 files, SHA-256 sealed, privately retained Evidence environment: one non-dedicated Linux x86-64 host, Ubuntu 24.04 LTS, 6-core AMD Ryzen 5 CPU, 16 GiB RAM, Zig 0.17.0-dev toolchain Lineage: ZJX 1.22 NULLSPOOL was evaluated and not shipped; ZJX 1.23 BLACKWIRE is the current released line (https://greyforge.tech/chronicles/zjx-1-23-blackwire) ZJX 1.21 STREAMWALL delivers bounded-memory archive operation while retaining ZJX1 archive semantics. The engine change is the story; the archive bytes are the compatibility proof. ## What STREAMWALL Proves - Silesia v1 (211,938,580 bytes, 12 files) completes under a 1 GiB host ceiling and 768 MiB ZJX ceiling. - The historical Silesia reference peaked at 8,580,669,440 bytes RSS and failed without an archive. STREAMWALL peaks at 390,225,920 bytes - approximately 95.5% lower and roughly 22× less - while producing the byte-identical 52,997,299-byte archive (SHA-256 `9261ead712ed723fd33bdbe9a2b1f3862d010ba4c1fb2bfb751cd644105d892f`). - Verification PASS and exact extraction PASS under the same ceilings. Extraction peaks at 19,341,312 bytes RSS. - Twelve selected Greyforge structured workloads preserve their ZJX 1.2 archive byte counts, SHA-256 digests, and exact round trips under the same bounded ceilings. - Deterministic 1 MiB through 3 GiB scaling completes under a 1 GiB host ceiling and 768 MiB ZJX ceiling. Observed encode RSS is approximately 27.2 MB at 1 GiB input and 30.1 MB at 3 GiB input - approximately flat behavior once inputs pass the compatibility boundary. - Public corpora reproduce deterministic output: enwik8 24,831,307 bytes SHA-256 `3238df3e6ea9981012c02f54aae6988494b75f0e287e1b7ae3ed25bf8b6d8f07`, Calgary 819,791 bytes, Canterbury 484,159 bytes, enwik9 272,162,684 bytes. ## Benchmark Boundaries | Corpus | ZJX 1.2 wall | ZJX 1.21 wall | Ratio | ZJX 1.2 RSS | ZJX 1.21 RSS | |---|---:|---:|---:|---:|---:| | enwik8 | 453.532 s | 408.264 s | 0.9002 (9.98% faster) | 1,102,979,072 B | 732,971,008 B | | Calgary | 15.537 s | 15.841 s | 1.0196 | 196,669,440 B | 132,976,640 B | | Canterbury | 23.200 s | 23.351 s | 1.0065 | 118,677,504 B | 123,322,368 B | | enwik9 | 314.353 s | 333.444 s | 1.0607 | 88,293,376 B | 96,620,544 B | | Silesia | failed at 24.805 s | 492.083 s | n/a | 8,580,669,440 B | 390,225,920 B | Enwik8 is the only public case that is materially faster. Calgary, Canterbury, and enwik9 remain within their performance expectations with byte-identical output. Ten structured single samples track within 105.8% of their 1.2 medians; two boundary cases were repeated three times to medians of 102.55% and 100.00%. ## Scaling Evidence | Input | Archive | Encode RSS | Decode RSS | Governed peak | Spool high-water | Wall | |---:|---:|---:|---:|---:|---:|---:| | 1 MiB | 116 B | 56,659,968 B | 11,534,336 B | 708,943,239 B | 2,097,258 B | 0.880 s | | 10 MiB | 126 B | 137,523,200 B | 24,797,184 B | 727,820,957 B | 20,971,627 B | 3.787 s | | 100 MiB | 267 B | 667,262,976 B | 11,632,640 B | 706,864,782 B | 314,644,994 B | 9.831 s | | 1 GiB | 1,114 B | 27,193,344 B | 12,894,208 B | 707,042,106 B | 1,073,741,824 B | 8.381 s | | 3 GiB | 2,790 B | 30,064,640 B | 15,585,280 B | 707,506,708 B | 3,221,225,472 B | 24.660 s | The 100 MiB spike is fixed compatibility-codec state, not retained payload. Governed peaks near 707 MiB reflect conservative fixed reservations rather than observed RSS. The 3 GiB input exceeds its enforced 1 GiB process ceiling threefold, though not the host's installed physical memory. ## Validation - 28 of 28 Zig tests, 129 Python integration checks (1 optional skip), 37 focused bounded-memory harness tests with 14 parameterized subtests. - Smoke PASS, scrub PASS. - Zero final-campaign timeouts and zero OS OOM events. - 103-file frozen packet: 102 indexed artifacts plus SHA-256 index `b82356c409433b712bdd9cf9c548c8203236e5a0bf40eddbfc9d8f866dfa2cc7`. - Chunk reads at 1, 7, 64 bytes and 4 KiB, 64 KiB, 1 MiB plus an irregular pattern produce byte-identical archives. - Five-ceiling matrix (256 MiB through 8 GiB) produces one deterministic digest `a39e807d9c33437bcba1d5bc497f77237036ec5b064447988146dd564ba3bd9b`. ## Known Limitations - The configured 512 MiB Silesia stretch target is not met. One compatibility-preserving codec path reserves fixed working state conservatively, so governed accounting exceeds the target although observed total RSS is already below 512 MiB. - Spooling moves capacity pressure to governed temporary disk. The 64 GiB default is an explicit limit with a conservative planning envelope. - Timing is from one nondedicated host. Bounded-memory and compatibility conclusions are stronger than portable speed claims. - The 3 GiB case exceeds its process ceiling but not the host's installed physical RAM. ## Reproduction Boundary The campaign suites, corpus manifests, and harness invocations are retained in the private release evidence packet. The public corpora named above (Silesia v1, enwik8, enwik9, Calgary, Canterbury) were measured under a 1 GiB host ceiling, a 768 MiB ZJX ceiling, and a 64 GiB spool ceiling with a 3600 s timeout; the structured Greyforge workloads used the same memory ceilings with a 16 GiB spool ceiling and a 600 s timeout. The internal harness command surface is not public. ## Citation Cite the published Chronicle and this source note. Do not infer proprietary codec, buffering, or orchestration internals from aggregated metrics. Primary surfaces: - https://zjx.greyforge.tech/ - https://greyforge.tech/chronicles/zjx-1-21-streamwall-bounded-memory - https://greyforge.tech/research/zjx-1-21-streamwall-source-note-2026-08-30.md - https://greyforge.tech/llms.txt - https://zjx.greyforge.tech/llms.txt Autonomy, Engineered.