[PDS-10{3841,4895}] Part 5: Don't Reuse Streams In The Stream Store

[jeremyk-91]

Thanks to @jackwickham and @j-baker for helping to puzzle through this issue!

Goals (and why):

• Don't break users who use storeStreams plural, and read the Sha256Hash data from the stream for whatever reason. Previously, this would invoke storeBlocksAndGetHashlessMetadata multiple times. But since the input stream was already consumed, it either returns nothing (e.g. if using ByteArrayInputStream), or throws.

Implementation Description (bullets):

• Store streams and generate metadata eagerly.

Testing (What was existing testing like? What have you done to improve it?):
Added two new tests validating

• streams are not used once closed
• that reading the metadata is allowed and won't cause SEVERE DATA CORRUPTION™️.

Concerns (what feedback would you like?):

• General correctness. Nothing too special.

Where should we start reviewing?: StreamTest

Priority (whenever / two weeks / yesterday): yesterday

[changelog-app]

Generate changelog in changelog/@unreleased

Type

• Feature
• Improvement
• Fix
• Break
• Deprecation
• Manual task
• Migration

Description

We no longer read and physically store streams lazily in the AtlasDB store when transactionally storing a stream (via storeStreams()).

Previously, users who stored and marked streams in a single transaction and subsequently referenced the returned Sha256Hash may fail in the following ways:

• if the provided InputStreams throw when they are read after being closed, these exceptions would be thrown out to the user.
• if the provided InputStreams do not throw when they are read after being closed, AtlasDB would erroneously write an empty block as the first block of the stream, and incorrect metadata of the stream being an empty stream.
  

Check the box to generate changelog(s)

• Generate changelog entry

[jeremyk-91]

(This is an unforked version of #4443 plus tests)

[OStevan]

Thanks for asking me to review.

[OStevan]

Looks good.

[jeremyk-91]

Thanks for the reviews!

[svc-autorelease]

Released 0.174.2