These methods are only used in tests but invoked on a merkle shred they
will always invalidate the shred because the merkle proof will no longer
verify. As a result the shred will not sanitize and blockstore will
avoid inserting them. Their use in tests will result in spurious test
coverage because the shreds will not be ingested.
The commit removes implementation of these methods for merkle shreds.
Follow up commits will entirely remove these methods from shreds api.
As a consequence of removing buffering when generating coding shreds:
https://github.com/solana-labs/solana/pull/25807
more coding shreds are generated than data shreds, and so
MAX_CODE_SHREDS_PER_SLOT needs to be adjusted accordingly.
The respective value is tied to ERASURE_BATCH_SIZE.
Shred versions are not verified until window-service where resources are
already wasted to sig-verify and deserialize shreds.
The commit verifies shred-version earlier in the pipeline in fetch stage.
In preparation of
https://github.com/solana-labs/solana/pull/25237
which adds a new shred variant with merkle tree branches, the commit
embeds versioning into shred binary by encoding a new ShredVariant type
at byte 65 of payload replacing previously ShredType at this offset.
enum ShredVariant {
LegacyCode, // 0b0101_1010
LegacyData, // 0b0101_1010
}
* 0b0101_1010 indicates a legacy coding shred, which is also equal to
ShredType::Code for backward compatibility.
* 0b1010_0101 indicates a legacy data shred, which is also equal to
ShredType::Data for backward compatibility.
Following commits will add merkle variants to this type:
enum ShredVariant {
LegacyCode, // 0b0101_1010
LegacyData, // 0b1010_0101
MerkleCode(/*proof_size:*/ u8), // 0b0100_????
MerkleData(/*proof_size:*/ u8), // 0b1000_????
}
Working towards revising shred struct to embed versioning so that a new
variant can contain merkle tree hashes of the erasure batch. To ease out
migration the commit adds more type-safety by distinguishing data vs
code shreds at the type level.
Additionally having both data and coding headers in each shred is
redundant as only one is relevant for each shred. The revised shred type
in this commit will only have one type-specific header.
https://github.com/solana-labs/solana/blob/c785f1ffc/ledger/src/shred.rs#L198-L203
Brooks Prumo
behzad nouri
Michael Vines