Crate windowed_infinity
source ·Expand description
This crate provides the WindowedInfinity struct and implementations of various traits to write to it.
Its primary is to wrap a small buffer such that writes to it advance a cursor over a larger imaginary buffer, only persisting writes to the small buffer. After the buffer has been processed, a new WindowedInfinity can be set up and the writing process repeated. This is wasteful when the writes are computationally expensive, but convenient when operations only rarely exceed the buffer.
A typical practical example of WindowedInfinity application is the implementation of CoAP
block-wise transfer according to RFC7959; a simpler
example is available in the demo.rs
example.
Features
The set of traits implemented by WindowedInfinity depends on the configured cargo features:
- With the
std
feature, it implements std::io::Write - With the
with_serde_cbor
feature, it uses serde_cbor’s trait unsealing feature to implement its Write trait. - Likewise, there are features for ciborium and minicbor. The minicbor version is a bit special
in that there is both a
with_minicbor
/with_minicbor_0_19
feature. - Starting at
with_minicbor_0_19
, features carry a version. This allows users of different minicbor versions to coexist in the same crate, and moreover ensures that the dependencies expressed in the Cargo.toml files to describe the requirements precisely. - With the
with_embedded_io_0_4
feature, the Write trait of embedded-io is implemented.
Crate size
Compared to the original plan of “doing one thing, and doing that right”, this crate has grown a bit, in that it contains trait implementations for several serializers, and extra mechanism for combining the own writer with others (from cryptographic digests or CRCs). Both these are temporary – once there is a 1.0 version of embedded-io, the Tee will be split out into a dedicated crate (with only compatibility re-exports and constructors / destructors remaining), and once serializers start using the stable embedded-io, no more writer implementations will need to be added.
Structs
Type Definitions
WindowedInfinity::tee_crc32()
and 64WindowedInfinity::tee_digest()