osobhandClaude Opus 5.5
db2554dd81
Range-read milestone M3, first half: a new crate with the block cache the
design makes mandatory for remote files and an HTTP backend, so
open_url("http://...") gives a clawhdf5::File over File::open_storage.
BlockCache wraps any Storage: aligned blocks (1 MiB by default, the size
docs/design/range-reads.md section 2 measured), LRU with a byte budget,
the missing blocks of one read_at/read_ranges fetched with one backend
read_ranges call as runs of consecutive blocks (a one-block gap filled to
merge runs, each request at most 8 MiB), and reads that miss more than
half the budget not kept. Thread-safe without holding the lock across a
fetch: a block being fetched is in flight, a second reader waits for it
instead of fetching it again, and a failed fetch fails its waiters and is
not cached. A backend holding the file in memory passes through.
HttpStorage (ureq, no TLS by default; `https` adds rustls with ring):
opening is one ranged GET of the first block, whose Content-Range gives
the length (the cache keeps the bytes). The file is pinned by a strong
ETag (If-Match), else Last-Modified (If-Unmodified-Since), and its length,
checked on every response: a change is RemoteError::FileChanged, never
mixed data. A server that ignores Range is refused without reading the
body unless a full download is allowed. Connection errors, timeouts,
408/429/5xx and short bodies are retried with exponential backoff;
Accept-Encoding: identity, and an encoded body is refused. read_ranges
fetches its ranges in parallel.
Tests (a std-only HTTP/1.1 server in tests/common/server.rs, also the
range_server example): every fixture read over HTTP gives File::open's
transcript (CLAWHDF5_REMOTE_CORPUS adds the conformance corpus), with
request counts per file with and without the cache; an h5py-written file
against libhdf5's values; a multi-block file fetched in whole blocks, each
once; a server ignoring Range; a file replaced mid-read (ETag,
Last-Modified, length only); truncated bodies and 503s (retried, then an
error, never cached); a slow server with 8 concurrent readers (no block
fetched twice); bad URLs, 404, encoded bodies, non-HDF5 data. The cache
has unit tests for coalescing, splitting, LRU order, large reads,
failures and concurrent in-flight dedup.
ci-test.sh: clawhdf5-remote joins the no-C default-build check, and its
https feature is linted.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
28 lines
956 B
TOML
28 lines
956 B
TOML
[package]
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name = "clawhdf5-remote"
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version = "2.7.0"
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edition = "2024"
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rust-version.workspace = true
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description = "Read HDF5 files over HTTP(S) range requests with clawhdf5, through a block cache"
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license = "MIT"
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repository = "https://git.redclaw.dev/quantumclaw/clawhdf5"
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readme = "README.md"
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keywords = ["hdf5", "http", "s3", "range-requests", "science"]
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categories = ["science", "network-programming"]
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[features]
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# Plain-HTTP range reads and the block cache: pure Rust, no TLS stack, no C.
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default = ["http"]
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http = ["dep:ureq"]
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# HTTPS through rustls (ring provider, Mozilla roots). ring compiles C and
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# assembly, so this is not part of the default build.
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https = ["http", "ureq/rustls"]
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[dependencies]
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clawhdf5 = { path = "../clawhdf5", version = "2.7.0" }
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clawhdf5-format = { path = "../clawhdf5-format", version = "2.7.0" }
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ureq = { version = "3.4", optional = true, default-features = false }
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[dev-dependencies]
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tempfile = { workspace = true }
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