This commit introduces a few major changes:
- (Breaking change) Limits now exist for maximum request body sizes.
- Buffers are preallocated for reading request bodies.
- Buffers are preallocated for decompressing request bodies.
- Gzip decoder instances are reused in a `sync.Pool` across requests.
The effect on garbage collection is dramatically fewer GC pauses, giving
a roughly 9% RPS improvement in load tests with gzipped request bodies.
For larger request sizes, the number of GC pauses is dramatically
reduced, although the peak pause time may increase by a few percent.
Implementation notes:
- The DecodingLimits handler enforces the max request body size both
through a Content-Length check, and a MaxBytesReader wrapper around
the payload.
- The DecodingLimits handler passes the gzip payload size limit down
using a context key.
Signed-off-by: Philip Conrad <philipaconrad@gmail.com>
Philip Conrad