[arch]
version = 0
scope = "fictional/"
title = "Fictional thumbnail service"
prompt = "arch/0"
generator = "fictional/example"

[source]
files = [
    { path = "fictional/src/cache.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
    { path = "fictional/src/decode.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
    { path = "fictional/src/gpu.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
    { path = "fictional/src/io.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
    { path = "fictional/src/lib.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
    { path = "fictional/src/pool.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
    { path = "fictional/src/queue.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
    { path = "fictional/src/worker.rs", hash = "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391" },
]
overview = """
This fictional crate turns image requests into reusable thumbnails.
A worker decodes files while the caller polls bounded replies.
The cache avoids repeated decoding and the caller uploads completed pixels."""

[lanes]
background = { title = "Worker thread" }
caller = { title = "Caller thread" }

[nodes]

[nodes.cache]
kind = "store"
title = "Thumbnail cache"
summary = "Reuses decoded thumbnails"
story = """
The cache stores completed thumbnails to avoid repeated decoding.
Keys include the requested size and content identity.
Missing entries trigger decoding and invalid entries are discarded."""
lane = "background"
refs = ["fictional/src/cache.rs::Cache"]
budget = "unknown"

[nodes.decoder]
kind = "component"
title = "Image decoder"
summary = "Converts source bytes into pixels"
story = """
The decoder produces thumbnail pixels so the caller avoids expensive work.
It checks dimensions before admitting output storage.
Malformed input produces an error reply."""
lane = "background"
refs = ["fictional/src/decode.rs:1::Decoder"]

[nodes.files]
kind = "io"
title = "Image files"
summary = "Supplies encoded image bytes"
story = """
The file reader supplies encoded bytes to the worker.
Reads belong to the worker to keep the caller responsive.
Missing files become error replies."""
lane = "background"
refs = ["fictional/src/io.rs::Reader"]

[nodes.frontend]
kind = "component"
title = "Request interface"
summary = "Accepts thumbnail requests"
story = """
The interface assigns request identities so replies can be matched.
It retains requests when the command queue is full.
Obsolete replies never replace the latest requested image."""
lane = "caller"
refs = ["fictional/src/lib.rs:1::Service"]

[nodes.gpu]
kind = "gpu"
title = "Thumbnail textures"
summary = "Retains uploaded thumbnail pixels"
story = """
Textures hold completed thumbnails for repeated drawing.
The caller owns texture handles until consumers release them.
Allocation failure leaves the previous image visible."""
lane = "caller"
refs = ["fictional/src/gpu.rs::Textures"]
budget = "unknown"

[nodes.inbox]
kind = "queue"
title = "Request queue"
summary = "Hands requests to the worker"
story = """
The bounded queue separates request submission from decoding.
Submitting never blocks the caller.
A full queue asks the caller to retry later."""
refs = ["fictional/src/queue.rs::Requests"]
budget = "unknown"

[nodes.memory]
kind = "memory"
title = "Pixel storage"
summary = "Owns admitted pixel buffers"
story = """
Pixel storage accounts for buffers used by decoding and replies.
Buffers remain owned while either side holds a reference.
Failed admission defers decoding instead of dropping live pixels."""
lane = "background"
refs = ["fictional/src/pool.rs::Pixels"]
budget = "unknown"

[nodes.outbox]
kind = "queue"
title = "Reply queue"
summary = "Publishes pixels and errors"
story = """
Replies carry request identities and shared pixel ownership.
The worker retains a reply while the queue is full.
A disconnected receiver ends publication."""
refs = ["fictional/src/queue.rs::Replies"]

[nodes.scheduler]
kind = "component"
title = "Request scheduler"
summary = "Chooses the next useful request"
story = """
The scheduler discards superseded requests to avoid wasted decoding.
It processes one admitted request at a time.
Cancellation preserves replies that have already been published."""
lane = "background"
refs = ["fictional/src/worker.rs::Scheduler"]

[nodes.session]
kind = "component"
title = "Service lifetime"
summary = "Starts and closes the worker"
story = """
The session owns worker lifetime so shutdown has one authority.
Closing stops admission before releasing communication endpoints.
Worker startup failure is returned to the caller."""
lane = "caller"
refs = ["fictional/src/lib.rs::Session"]

[nodes.uploader]
kind = "component"
title = "Texture uploader"
summary = "Turns completed replies into textures"
story = """
The uploader polls replies and checks request identity before upload.
GPU work stays on the caller thread.
Failed uploads preserve the previous texture and report the error."""
lane = "caller"
refs = ["fictional/src/gpu.rs::Uploader"]

[nodes.worker]
kind = "thread"
title = "Decode worker"
summary = "Owns file reads and decoding"
story = """
One persistent worker owns scheduling, file reads, and decoding.
It publishes shared payloads without lending mutable state to the caller.
Queue disconnection starts orderly shutdown."""
lane = "background"
refs = ["fictional/src/worker.rs::Worker"]
child = "fictional/arch/worker.toml"

[edges]
allocate = { from = "decoder", to = "memory", kind = "allocates_from", label = "admit pixels" }
cache_read = { from = "scheduler", to = "cache", kind = "reads", label = "reuse" }
cache_write = { from = "decoder", to = "cache", kind = "writes", label = "completed thumbnail" }
decode = { from = "scheduler", to = "decoder", kind = "calls", label = "cache miss" }
poll = { from = "uploader", to = "outbox", kind = "reads", label = "nonblocking poll" }
publish = { from = "worker", to = "outbox", kind = "sends", label = "pixels or error" }
read_file = { from = "worker", to = "files", kind = "reads", label = "encoded bytes" }
schedule = { from = "worker", to = "scheduler", kind = "owns", label = "request selection" }
spawn = { from = "session", to = "worker", kind = "spawns", label = "once per service" }
submit = { from = "frontend", to = "inbox", kind = "sends", label = "retry on full" }
take_request = { from = "worker", to = "inbox", kind = "reads", label = "next request" }
upload = { from = "uploader", to = "gpu", kind = "uploads_to", label = "current reply" }