feat(cluster): add clustered storage backend with QUIC transport, erasure coding, and shard management

rust/src/cluster/metadata.rs

@@ -0,0 +1,85 @@
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+/// Full manifest describing how an object is stored across erasure-coded shards.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ObjectManifest {
+    /// Bucket name
+    pub bucket: String,
+    /// Object key
+    pub key: String,
+    /// Unique version ID for this write
+    pub version_id: String,
+    /// Total object size in bytes
+    pub size: u64,
+    /// MD5 hex digest of the complete object
+    pub content_md5: String,
+    /// Content type
+    pub content_type: String,
+    /// User metadata (x-amz-meta-*, content-type, etc.)
+    pub metadata: HashMap<String, String>,
+    /// When the object was created
+    pub created_at: String,
+    /// Last modified timestamp
+    pub last_modified: String,
+    /// Number of data shards used
+    pub data_shards: usize,
+    /// Number of parity shards used
+    pub parity_shards: usize,
+    /// Chunk size in bytes (last chunk may be smaller)
+    pub chunk_size: usize,
+    /// Per-chunk shard placement info
+    pub chunks: Vec<ChunkManifest>,
+}
+
+/// Describes the shards for a single chunk of an object.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ChunkManifest {
+    /// Index of this chunk (0-based)
+    pub chunk_index: u32,
+    /// Actual data size of this chunk (before erasure coding)
+    pub data_size: usize,
+    /// Where each shard was placed
+    pub shard_placements: Vec<ShardPlacement>,
+}
+
+/// Describes where a specific shard is stored.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ShardPlacement {
+    /// Shard index within the erasure set (0..data_shards+parity_shards)
+    pub shard_index: u32,
+    /// Node that holds this shard
+    pub node_id: String,
+    /// Drive ID on that node
+    pub drive_id: String,
+    /// CRC32C checksum of the shard data
+    pub checksum: u32,
+    /// Size of the shard data in bytes
+    pub shard_size: usize,
+}
+
+/// Manifest for a multipart upload in progress.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct MultipartUploadManifest {
+    pub upload_id: String,
+    pub bucket: String,
+    pub key: String,
+    pub initiated: String,
+    pub metadata: HashMap<String, String>,
+    /// Per-part manifests, keyed by part number.
+    pub parts: HashMap<u32, PartManifest>,
+}
+
+/// Manifest for a single part of a multipart upload.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct PartManifest {
+    pub part_number: u32,
+    pub size: u64,
+    pub md5: String,
+    pub chunks: Vec<ChunkManifest>,
+}