Add missing EC constants MAX_SHARD_COUNT and MIN_TOTAL_DISKS

seaweed-volume/src/storage/erasure_coding/ec_shard.rs

@@ -8,6 +8,8 @@ use crate::storage::types::*;
 pub const DATA_SHARDS_COUNT: usize = 10;
 pub const PARITY_SHARDS_COUNT: usize = 4;
 pub const TOTAL_SHARDS_COUNT: usize = DATA_SHARDS_COUNT + PARITY_SHARDS_COUNT;
+pub const MAX_SHARD_COUNT: usize = 32;
+pub const MIN_TOTAL_DISKS: usize = TOTAL_SHARDS_COUNT / PARITY_SHARDS_COUNT + 1;
 pub const ERASURE_CODING_LARGE_BLOCK_SIZE: usize = 1024 * 1024 * 1024; // 1GB
 pub const ERASURE_CODING_SMALL_BLOCK_SIZE: usize = 1024 * 1024; // 1MB
 

seaweed-volume/src/storage/erasure_coding/mod.rs

@@ -10,6 +10,7 @@ pub mod ec_shard;
 pub mod ec_volume;
 
 pub use ec_shard::{
-    EcVolumeShard, ShardId, DATA_SHARDS_COUNT, PARITY_SHARDS_COUNT, TOTAL_SHARDS_COUNT,
+    EcVolumeShard, ShardId, DATA_SHARDS_COUNT, MAX_SHARD_COUNT, MIN_TOTAL_DISKS,
+    PARITY_SHARDS_COUNT, TOTAL_SHARDS_COUNT,
 };
 pub use ec_volume::EcVolume;