Feature/vpaamp 237 unify cache fragment resolve symbols

[DomSyna]

Summary
Stage 3 completes the rename work begun in stages 1 and 2. No behavioural change — pure mechanical rename, lock-scope tidy, and comment cleanup.

Changes

• Rename all ring-buffer symbols: mCachedFragmentChunks* to mCachedFragment*, numberOfFragmentChunksCached to numberOfFragmentsCached, fragmentChunkIdxTo* to fragmentIdxTo*, WaitForCachedFragmentChunk* to WaitForCachedFragment*, UpdateTSAfterChunk* to UpdateTSAfter*, GetFetchChunkBuffer to GetFetchBuffer, SetCachedFragmentChunksSize to SetCachedFragmentSize, eAAMPConfig_MaxFragmentChunkCached to eAAMPConfig_MaxFragmentCached
• Replace fixed-size C array mCachedFragmentChunks[] with std::array<CachedFragment, DEFAULT_LLD_CACHED_FRAGMENTS_PER_TRACK> (RAII, bounds-safe)
• Consolidate per-track lifetime counter writes under mTrackParamsMutex; make Get*Duration() accessors lock-taking; document lock order
• Fix stale doxygen and inline comments in streamabstraction.cpp, StreamAbstractionAAMP.h, AampConfig.h, and AampDefine.h. Legitimate "chunk" references (HTTP chunked transfer, CMAF sub-segments, ABR speed estimation, ISOBMFF boxes) left unchanged.
• Propagate renames to all unit test fakes, mocks, and test files

[Copilot]

Pull request overview

This PR completes the “chunk-cache” → “fragment-cache” mechanical rename across the player and unit tests, while also tightening some lock scoping and converting the per-track cached fragment ring buffer to a std::array-backed storage.

Changes:

• Renamed MediaTrack/StreamAbstraction/Config symbols from *Chunk* to *Fragment* (including config enum + defaults) and propagated the renames through fakes/mocks/tests.
• Replaced the per-track fixed C array cache with std::array<CachedFragment, DEFAULT_LLD_CACHED_FRAGMENTS_PER_TRACK> and introduced an “active window” size (mCachedFragmentSize).
• Consolidated/clarified locking around track lifetime counters and updated related comments/doxygen.

Reviewed changes

Copilot reviewed 24 out of 24 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/utests/tests/TrackInjectTests/TrackInjectTests.cpp	Updates unit test references to new fragment-cache symbols and config enum.
test/utests/tests/StreamAbstractionAAMP/FunctionalTests.cpp	Updates mocked config lookups to eAAMPConfig_MaxLLDFragmentCached.
test/utests/tests/StreamAbstractionAAMP_MPD/StreamSelectionTest.cpp	Renames config enum usage in MPD stream selection tests.
test/utests/tests/StreamAbstractionAAMP_MPD/LinearFOGTests.cpp	Renames config enum usage in MPD FOG tests.
test/utests/tests/StreamAbstractionAAMP_MPD/FunctionalTests.cpp	Renames config enum usage in MPD functional tests.
test/utests/tests/StreamAbstractionAAMP_MPD/FetcherLoopTests.cpp	Renames config enum usage in MPD fetcher loop tests.
test/utests/tests/StreamAbstractionAAMP_MPD/AudioOnlyTests.cpp	Renames config enum usage in MPD audio-only tests.
test/utests/tests/StreamAbstractionAAMP_HLS/FunctionalTests.cpp	Updates HLS track state tests to new fragment-cache APIs/fields.
test/utests/tests/MediaTrackTests/MediaTrackTests.cpp	Updates MediaTrack unit tests to new fragment-cache APIs/fields.
test/utests/tests/MediaStreamContextTests/MediaStreamContextTests.cpp	Updates mocked GetFetch* API call names.
test/utests/tests/MediaStreamContextTests/FragmentDownloadTests.cpp	Updates mocked GetFetch*/UpdateTSAfter* calls and cached-count fields.
test/utests/tests/FragmentCollectorAdTests/AdSelectionTests.cpp	Renames config enum usage in ad selection tests.
test/utests/tests/CacheFragmentTests/CacheFragmentTests.cpp	Updates cached-count field name and config enum usage.
test/utests/mocks/MockMediaTrack.h	Renames mocked methods to GetFetchBuffer / UpdateTSAfterFetch.
test/utests/fakes/FakeStreamAbstractionAamp.cpp	Updates fake shims to delegate to renamed mock methods/APIs.
StreamAbstractionAAMP.h	Introduces std::array ring buffer, renames APIs/fields/CVs, adjusts getters.
streamabstraction.cpp	Updates core cache/inject logic to renamed fields + adds lock-order docs and new locked accessor.
priv_aamp.cpp	Updates stop-path unblock call to renamed API.
MediaStreamContext.cpp	Renames calls to fragment-cache APIs (WaitForCachedFragmentInjected, GetFetchBuffer, UpdateTSAfterFetch).
fragmentcollector_mpd.cpp	Propagates fragment-cache renames in MPD TSB/reader paths and cache sizing.
fragmentcollector_hls.cpp	Propagates fragment-cache renames in HLS fetch paths and comments.
AampDefine.h	Renames default constant to DEFAULT_LLD_CACHED_FRAGMENTS_PER_TRACK.
AampConfig.h	Renames config enum to eAAMPConfig_MaxLLDFragmentCached.
AampConfig.cpp	Updates config lookup table mapping for renamed enum/default.

Comments suppressed due to low confidence (1)

streamabstraction.cpp:4699

• SetCachedFragmentSize() validates against maxLLDCachedFragmentsPerTrack but does not enforce the actual backing storage capacity (mCachedFragment is a fixed-size std::array). If the config value exceeds DEFAULT_LLD_CACHED_FRAGMENTS_PER_TRACK, mCachedFragmentSize can be set larger than the array and later loops/indexing (e.g., FlushFragments, modulo wraps) will go out-of-bounds. Clamp size to mCachedFragment.size() (and handle invalid/0 sizes by falling back to a safe default) rather than just logging and leaving the previous value unchanged.

void MediaTrack::SetCachedFragmentSize(size_t size)
{
	if (size > 0 && size <= maxLLDCachedFragmentsPerTrack)
	{
		AAMPLOG_TRACE("Set mCachedFragment size:%zu successfully", size);
		mCachedFragmentSize = size;
	}
	else
	{
		AAMPLOG_ERR("Failed to set size:%zu", size);
	}
}

[DomSyna]

Already covered by VPAAMP-180