Refactor: Introduce content checksums and improve multipart/object metadata handling (#671)

* feat:  adapt to s3s typed etag support

* refactor: move replication struct to rustfs_filemeta, fix filemeta transition bug

* add head_object checksum, filter object metadata output

* fix multipart checksum

* fix multipart checksum

* add content md5,sha256 check

* fix test

* fix cargo

---------

Co-authored-by: overtrue <anzhengchao@gmail.com>

crates/filemeta/src/fileinfo.rs

@@ -284,6 +284,7 @@ impl FileInfo {
         Ok(t)
     }
 
+    #[allow(clippy::too_many_arguments)]
     pub fn add_object_part(
         &mut self,
         num: usize,
@@ -292,6 +293,7 @@ impl FileInfo {
         mod_time: Option<OffsetDateTime>,
         actual_size: i64,
         index: Option<Bytes>,
+        checksums: Option<HashMap<String, String>>,
     ) {
         let part = ObjectPartInfo {
             etag,
@@ -300,7 +302,7 @@ impl FileInfo {
             mod_time,
             actual_size,
             index,
-            checksums: None,
+            checksums,
             error: None,
         };
 

crates/filemeta/src/filemeta.rs

@@ -15,9 +15,12 @@
 use crate::error::{Error, Result};
 use crate::fileinfo::{ErasureAlgo, ErasureInfo, FileInfo, FileInfoVersions, ObjectPartInfo, RawFileInfo};
 use crate::filemeta_inline::InlineData;
-use crate::{ReplicationStatusType, VersionPurgeStatusType};
+use crate::{
+    ReplicationState, ReplicationStatusType, VersionPurgeStatusType, replication_statuses_map, version_purge_statuses_map,
+};
 use byteorder::ByteOrder;
 use bytes::Bytes;
+use rustfs_utils::http::AMZ_BUCKET_REPLICATION_STATUS;
 use rustfs_utils::http::headers::{
     self, AMZ_META_UNENCRYPTED_CONTENT_LENGTH, AMZ_META_UNENCRYPTED_CONTENT_MD5, AMZ_STORAGE_CLASS, RESERVED_METADATA_PREFIX,
     RESERVED_METADATA_PREFIX_LOWER, VERSION_PURGE_STATUS_KEY,
@@ -30,6 +33,7 @@ use std::hash::Hasher;
 use std::io::{Read, Write};
 use std::{collections::HashMap, io::Cursor};
 use time::OffsetDateTime;
+use time::format_description::well_known::Rfc3339;
 use tokio::io::AsyncRead;
 use tracing::error;
 use uuid::Uuid;
@@ -1742,7 +1746,25 @@ impl MetaObject {
             }
         }
 
-        // todo: ReplicationState,Delete
+        let replication_state_internal = get_internal_replication_state(&metadata);
+
+        let mut deleted = false;
+
+        if let Some(v) = replication_state_internal.as_ref() {
+            if !v.composite_version_purge_status().is_empty() {
+                deleted = true;
+            }
+
+            let st = v.composite_replication_status();
+            if !st.is_empty() {
+                metadata.insert(AMZ_BUCKET_REPLICATION_STATUS.to_string(), st.to_string());
+            }
+        }
+
+        let checksum = self
+            .meta_sys
+            .get(format!("{RESERVED_METADATA_PREFIX_LOWER}crc").as_str())
+            .map(|v| Bytes::from(v.clone()));
 
         let erasure = ErasureInfo {
             algorithm: self.erasure_algorithm.to_string(),
@@ -1754,6 +1776,26 @@ impl MetaObject {
             ..Default::default()
         };
 
+        let transition_status = self
+            .meta_sys
+            .get(format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITION_STATUS}").as_str())
+            .map(|v| String::from_utf8_lossy(v).to_string())
+            .unwrap_or_default();
+        let transitioned_objname = self
+            .meta_sys
+            .get(format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITIONED_OBJECTNAME}").as_str())
+            .map(|v| String::from_utf8_lossy(v).to_string())
+            .unwrap_or_default();
+        let transition_version_id = self
+            .meta_sys
+            .get(format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITIONED_VERSION_ID}").as_str())
+            .map(|v| Uuid::from_slice(v.as_slice()).unwrap_or_default());
+        let transition_tier = self
+            .meta_sys
+            .get(format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITION_TIER}").as_str())
+            .map(|v| String::from_utf8_lossy(v).to_string())
+            .unwrap_or_default();
+
         FileInfo {
             version_id,
             erasure,
@@ -1764,6 +1806,13 @@ impl MetaObject {
             volume: volume.to_string(),
             parts,
             metadata,
+            replication_state_internal,
+            deleted,
+            checksum,
+            transition_status,
+            transitioned_objname,
+            transition_version_id,
+            transition_tier,
             ..Default::default()
         }
     }
@@ -1904,6 +1953,38 @@ impl From<FileInfo> for MetaObject {
             }
         }
 
+        if !value.transition_status.is_empty() {
+            meta_sys.insert(
+                format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITION_STATUS}"),
+                value.transition_status.as_bytes().to_vec(),
+            );
+        }
+
+        if !value.transitioned_objname.is_empty() {
+            meta_sys.insert(
+                format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITIONED_OBJECTNAME}"),
+                value.transitioned_objname.as_bytes().to_vec(),
+            );
+        }
+
+        if let Some(vid) = &value.transition_version_id {
+            meta_sys.insert(
+                format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITIONED_VERSION_ID}"),
+                vid.as_bytes().to_vec(),
+            );
+        }
+
+        if !value.transition_tier.is_empty() {
+            meta_sys.insert(
+                format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITION_TIER}"),
+                value.transition_tier.as_bytes().to_vec(),
+            );
+        }
+
+        if let Some(content_hash) = value.checksum {
+            meta_sys.insert(format!("{RESERVED_METADATA_PREFIX_LOWER}crc"), content_hash.to_vec());
+        }
+
         Self {
             version_id: value.version_id,
             data_dir: value.data_dir,
@@ -1927,6 +2008,50 @@ impl From<FileInfo> for MetaObject {
     }
 }
 
+fn get_internal_replication_state(metadata: &HashMap<String, String>) -> Option<ReplicationState> {
+    let mut rs = ReplicationState::default();
+    let mut has = false;
+
+    for (k, v) in metadata.iter() {
+        if k == VERSION_PURGE_STATUS_KEY {
+            rs.version_purge_status_internal = Some(v.clone());
+            rs.purge_targets = version_purge_statuses_map(v.as_str());
+            has = true;
+            continue;
+        }
+
+        if let Some(sub_key) = k.strip_prefix(RESERVED_METADATA_PREFIX_LOWER) {
+            match sub_key {
+                "replica-timestamp" => {
+                    has = true;
+                    rs.replica_timestamp = Some(OffsetDateTime::parse(v, &Rfc3339).unwrap_or(OffsetDateTime::UNIX_EPOCH));
+                }
+                "replica-status" => {
+                    has = true;
+                    rs.replica_status = ReplicationStatusType::from(v.as_str());
+                }
+                "replication-timestamp" => {
+                    has = true;
+                    rs.replication_timestamp = Some(OffsetDateTime::parse(v, &Rfc3339).unwrap_or(OffsetDateTime::UNIX_EPOCH))
+                }
+                "replication-status" => {
+                    has = true;
+                    rs.replication_status_internal = Some(v.clone());
+                    rs.targets = replication_statuses_map(v.as_str());
+                }
+                _ => {
+                    if let Some(arn) = sub_key.strip_prefix("replication-reset-") {
+                        has = true;
+                        rs.reset_statuses_map.insert(arn.to_string(), v.clone());
+                    }
+                }
+            }
+        }
+    }
+
+    if has { Some(rs) } else { None }
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq)]
 pub struct MetaDeleteMarker {
     #[serde(rename = "ID")]
@@ -1939,24 +2064,51 @@ pub struct MetaDeleteMarker {
 
 impl MetaDeleteMarker {
     pub fn free_version(&self) -> bool {
-        self.meta_sys.contains_key(FREE_VERSION_META_HEADER)
+        self.meta_sys
+            .contains_key(format!("{RESERVED_METADATA_PREFIX_LOWER}{FREE_VERSION}").as_str())
     }
 
     pub fn into_fileinfo(&self, volume: &str, path: &str, _all_parts: bool) -> FileInfo {
-        let metadata = self.meta_sys.clone();
+        let metadata = self
+            .meta_sys
+            .clone()
+            .into_iter()
+            .map(|(k, v)| (k, String::from_utf8_lossy(&v).to_string()))
+            .collect();
+        let replication_state_internal = get_internal_replication_state(&metadata);
 
-        FileInfo {
+        let mut fi = FileInfo {
             version_id: self.version_id.filter(|&vid| !vid.is_nil()),
             name: path.to_string(),
             volume: volume.to_string(),
             deleted: true,
             mod_time: self.mod_time,
-            metadata: metadata
-                .into_iter()
-                .map(|(k, v)| (k, String::from_utf8_lossy(&v).to_string()))
-                .collect(),
+            metadata,
+            replication_state_internal,
             ..Default::default()
+        };
+
+        if self.free_version() {
+            fi.set_tier_free_version();
+            fi.transition_tier = self
+                .meta_sys
+                .get(format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITION_TIER}").as_str())
+                .map(|v| String::from_utf8_lossy(v).to_string())
+                .unwrap_or_default();
+
+            fi.transitioned_objname = self
+                .meta_sys
+                .get(format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITIONED_OBJECTNAME}").as_str())
+                .map(|v| String::from_utf8_lossy(v).to_string())
+                .unwrap_or_default();
+
+            fi.transition_version_id = self
+                .meta_sys
+                .get(format!("{RESERVED_METADATA_PREFIX_LOWER}{TRANSITIONED_VERSION_ID}").as_str())
+                .map(|v| Uuid::from_slice(v.as_slice()).unwrap_or_default());
         }
+
+        fi
     }
 
     pub fn unmarshal_msg(&mut self, buf: &[u8]) -> Result<u64> {
@@ -2160,8 +2312,6 @@ pub enum Flags {
     InlineData = 1 << 2,
 }
 
-const FREE_VERSION_META_HEADER: &str = "free-version";
-
 // mergeXLV2Versions
 pub fn merge_file_meta_versions(
     mut quorum: usize,

crates/filemeta/src/replication.rs

@@ -1,8 +1,36 @@
+use bytes::Bytes;
 use core::fmt;
+use regex::Regex;
+use rustfs_utils::http::RESERVED_METADATA_PREFIX_LOWER;
 use serde::{Deserialize, Serialize};
+use std::any::Any;
 use std::collections::HashMap;
 use std::time::Duration;
 use time::OffsetDateTime;
+use uuid::Uuid;
+
+pub const REPLICATION_RESET: &str = "replication-reset";
+pub const REPLICATION_STATUS: &str = "replication-status";
+
+// ReplicateQueued - replication being queued trail
+pub const REPLICATE_QUEUED: &str = "replicate:queue";
+
+// ReplicateExisting - audit trail for existing objects replication
+pub const REPLICATE_EXISTING: &str = "replicate:existing";
+// ReplicateExistingDelete - audit trail for delete replication triggered for existing delete markers
+pub const REPLICATE_EXISTING_DELETE: &str = "replicate:existing:delete";
+
+// ReplicateMRF - audit trail for replication from Most Recent Failures (MRF) queue
+pub const REPLICATE_MRF: &str = "replicate:mrf";
+// ReplicateIncoming - audit trail of inline replication
+pub const REPLICATE_INCOMING: &str = "replicate:incoming";
+// ReplicateIncomingDelete - audit trail of inline replication of deletes.
+pub const REPLICATE_INCOMING_DELETE: &str = "replicate:incoming:delete";
+
+// ReplicateHeal - audit trail for healing of failed/pending replications
+pub const REPLICATE_HEAL: &str = "replicate:heal";
+// ReplicateHealDelete - audit trail of healing of failed/pending delete replications.
+pub const REPLICATE_HEAL_DELETE: &str = "replicate:heal:delete";
 
 /// StatusType of Replication for x-amz-replication-status header
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default, Hash)]
@@ -492,3 +520,371 @@ impl ReplicatedInfos {
         ReplicationAction::None
     }
 }
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct MrfReplicateEntry {
+    #[serde(rename = "bucket")]
+    pub bucket: String,
+
+    #[serde(rename = "object")]
+    pub object: String,
+
+    #[serde(skip_serializing, skip_deserializing)]
+    pub version_id: Option<Uuid>,
+
+    #[serde(rename = "retryCount")]
+    pub retry_count: i32,
+
+    #[serde(skip_serializing, skip_deserializing)]
+    pub size: i64,
+}
+
+pub trait ReplicationWorkerOperation: Any + Send + Sync {
+    fn to_mrf_entry(&self) -> MrfReplicateEntry;
+    fn as_any(&self) -> &dyn Any;
+    fn get_bucket(&self) -> &str;
+    fn get_object(&self) -> &str;
+    fn get_size(&self) -> i64;
+    fn is_delete_marker(&self) -> bool;
+    fn get_op_type(&self) -> ReplicationType;
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct ReplicateTargetDecision {
+    pub replicate: bool,
+    pub synchronous: bool,
+    pub arn: String,
+    pub id: String,
+}
+
+impl ReplicateTargetDecision {
+    pub fn new(arn: String, replicate: bool, sync: bool) -> Self {
+        Self {
+            replicate,
+            synchronous: sync,
+            arn,
+            id: String::new(),
+        }
+    }
+}
+
+impl fmt::Display for ReplicateTargetDecision {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{};{};{};{}", self.replicate, self.synchronous, self.arn, self.id)
+    }
+}
+
+/// ReplicateDecision represents replication decision for each target
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ReplicateDecision {
+    pub targets_map: HashMap<String, ReplicateTargetDecision>,
+}
+
+impl ReplicateDecision {
+    pub fn new() -> Self {
+        Self {
+            targets_map: HashMap::new(),
+        }
+    }
+
+    /// Returns true if at least one target qualifies for replication
+    pub fn replicate_any(&self) -> bool {
+        self.targets_map.values().any(|t| t.replicate)
+    }
+
+    /// Returns true if at least one target qualifies for synchronous replication
+    pub fn is_synchronous(&self) -> bool {
+        self.targets_map.values().any(|t| t.synchronous)
+    }
+
+    /// Updates ReplicateDecision with target's replication decision
+    pub fn set(&mut self, target: ReplicateTargetDecision) {
+        self.targets_map.insert(target.arn.clone(), target);
+    }
+
+    /// Returns a stringified representation of internal replication status with all targets marked as `PENDING`
+    pub fn pending_status(&self) -> Option<String> {
+        let mut result = String::new();
+        for target in self.targets_map.values() {
+            if target.replicate {
+                result.push_str(&format!("{}={};", target.arn, ReplicationStatusType::Pending.as_str()));
+            }
+        }
+        if result.is_empty() { None } else { Some(result) }
+    }
+}
+
+impl fmt::Display for ReplicateDecision {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut result = String::new();
+        for (key, value) in &self.targets_map {
+            result.push_str(&format!("{key}={value},"));
+        }
+        write!(f, "{}", result.trim_end_matches(','))
+    }
+}
+
+impl Default for ReplicateDecision {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// parse k-v pairs of target ARN to stringified ReplicateTargetDecision delimited by ',' into a
+// ReplicateDecision struct
+pub fn parse_replicate_decision(_bucket: &str, s: &str) -> std::io::Result<ReplicateDecision> {
+    let mut decision = ReplicateDecision::new();
+
+    if s.is_empty() {
+        return Ok(decision);
+    }
+
+    for p in s.split(',') {
+        if p.is_empty() {
+            continue;
+        }
+
+        let slc = p.split('=').collect::<Vec<&str>>();
+        if slc.len() != 2 {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidInput,
+                format!("invalid replicate decision format: {s}"),
+            ));
+        }
+
+        let tgt_str = slc[1].trim_matches('"');
+        let tgt = tgt_str.split(';').collect::<Vec<&str>>();
+        if tgt.len() != 4 {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidInput,
+                format!("invalid replicate decision format: {s}"),
+            ));
+        }
+
+        let tgt = ReplicateTargetDecision {
+            replicate: tgt[0] == "true",
+            synchronous: tgt[1] == "true",
+            arn: tgt[2].to_string(),
+            id: tgt[3].to_string(),
+        };
+        decision.targets_map.insert(slc[0].to_string(), tgt);
+    }
+
+    Ok(decision)
+
+    // r = ReplicateDecision{
+    // 	targetsMap: make(map[string]replicateTargetDecision),
+    // }
+    // if len(s) == 0 {
+    // 	return
+    // }
+    // for _, p := range strings.Split(s, ",") {
+    // 	if p == "" {
+    // 		continue
+    // 	}
+    // 	slc := strings.Split(p, "=")
+    // 	if len(slc) != 2 {
+    // 		return r, errInvalidReplicateDecisionFormat
+    // 	}
+    // 	tgtStr := strings.TrimSuffix(strings.TrimPrefix(slc[1], `"`), `"`)
+    // 	tgt := strings.Split(tgtStr, ";")
+    // 	if len(tgt) != 4 {
+    // 		return r, errInvalidReplicateDecisionFormat
+    // 	}
+    // 	r.targetsMap[slc[0]] = replicateTargetDecision{Replicate: tgt[0] == "true", Synchronous: tgt[1] == "true", Arn: tgt[2], ID: tgt[3]}
+    // }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ReplicateObjectInfo {
+    pub name: String,
+    pub size: i64,
+    pub actual_size: i64,
+    pub bucket: String,
+    pub version_id: Option<Uuid>,
+    pub etag: Option<String>,
+    pub mod_time: Option<OffsetDateTime>,
+    pub replication_status: ReplicationStatusType,
+    pub replication_status_internal: Option<String>,
+    pub delete_marker: bool,
+    pub version_purge_status_internal: Option<String>,
+    pub version_purge_status: VersionPurgeStatusType,
+    pub replication_state: Option<ReplicationState>,
+    pub op_type: ReplicationType,
+    pub event_type: String,
+    pub dsc: ReplicateDecision,
+    pub existing_obj_resync: ResyncDecision,
+    pub target_statuses: HashMap<String, ReplicationStatusType>,
+    pub target_purge_statuses: HashMap<String, VersionPurgeStatusType>,
+    pub replication_timestamp: Option<OffsetDateTime>,
+    pub ssec: bool,
+    pub user_tags: String,
+    pub checksum: Option<Bytes>,
+    pub retry_count: u32,
+}
+
+impl ReplicationWorkerOperation for ReplicateObjectInfo {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn to_mrf_entry(&self) -> MrfReplicateEntry {
+        MrfReplicateEntry {
+            bucket: self.bucket.clone(),
+            object: self.name.clone(),
+            version_id: self.version_id,
+            retry_count: self.retry_count as i32,
+            size: self.size,
+        }
+    }
+
+    fn get_bucket(&self) -> &str {
+        &self.bucket
+    }
+
+    fn get_object(&self) -> &str {
+        &self.name
+    }
+
+    fn get_size(&self) -> i64 {
+        self.size
+    }
+
+    fn is_delete_marker(&self) -> bool {
+        self.delete_marker
+    }
+
+    fn get_op_type(&self) -> ReplicationType {
+        self.op_type
+    }
+}
+
+lazy_static::lazy_static! {
+    static ref REPL_STATUS_REGEX: Regex = Regex::new(r"([^=].*?)=([^,].*?);").unwrap();
+}
+
+impl ReplicateObjectInfo {
+    /// Returns replication status of a target
+    pub fn target_replication_status(&self, arn: &str) -> ReplicationStatusType {
+        let binding = self.replication_status_internal.clone().unwrap_or_default();
+        let captures = REPL_STATUS_REGEX.captures_iter(&binding);
+        for cap in captures {
+            if cap.len() == 3 && &cap[1] == arn {
+                return ReplicationStatusType::from(&cap[2]);
+            }
+        }
+        ReplicationStatusType::default()
+    }
+
+    /// Returns the relevant info needed by MRF
+    pub fn to_mrf_entry(&self) -> MrfReplicateEntry {
+        MrfReplicateEntry {
+            bucket: self.bucket.clone(),
+            object: self.name.clone(),
+            version_id: self.version_id,
+            retry_count: self.retry_count as i32,
+            size: self.size,
+        }
+    }
+}
+
+// constructs a replication status map from string representation
+pub fn replication_statuses_map(s: &str) -> HashMap<String, ReplicationStatusType> {
+    let mut targets = HashMap::new();
+    let rep_stat_matches = REPL_STATUS_REGEX.captures_iter(s).map(|c| c.extract());
+    for (_, [arn, status]) in rep_stat_matches {
+        if arn.is_empty() {
+            continue;
+        }
+        let status = ReplicationStatusType::from(status);
+        targets.insert(arn.to_string(), status);
+    }
+    targets
+}
+
+// constructs a version purge status map from string representation
+pub fn version_purge_statuses_map(s: &str) -> HashMap<String, VersionPurgeStatusType> {
+    let mut targets = HashMap::new();
+    let purge_status_matches = REPL_STATUS_REGEX.captures_iter(s).map(|c| c.extract());
+    for (_, [arn, status]) in purge_status_matches {
+        if arn.is_empty() {
+            continue;
+        }
+        let status = VersionPurgeStatusType::from(status);
+        targets.insert(arn.to_string(), status);
+    }
+    targets
+}
+
+pub fn get_replication_state(rinfos: &ReplicatedInfos, prev_state: &ReplicationState, _vid: Option<String>) -> ReplicationState {
+    let reset_status_map: Vec<(String, String)> = rinfos
+        .targets
+        .iter()
+        .filter(|v| !v.resync_timestamp.is_empty())
+        .map(|t| (target_reset_header(t.arn.as_str()), t.resync_timestamp.clone()))
+        .collect();
+
+    let repl_statuses = rinfos.replication_status_internal();
+    let vpurge_statuses = rinfos.version_purge_status_internal();
+
+    let mut reset_statuses_map = prev_state.reset_statuses_map.clone();
+    for (key, value) in reset_status_map {
+        reset_statuses_map.insert(key, value);
+    }
+
+    ReplicationState {
+        replicate_decision_str: prev_state.replicate_decision_str.clone(),
+        reset_statuses_map,
+        replica_timestamp: prev_state.replica_timestamp,
+        replica_status: prev_state.replica_status.clone(),
+        targets: replication_statuses_map(&repl_statuses.clone().unwrap_or_default()),
+        replication_status_internal: repl_statuses,
+        replication_timestamp: rinfos.replication_timestamp,
+        purge_targets: version_purge_statuses_map(&vpurge_statuses.clone().unwrap_or_default()),
+        version_purge_status_internal: vpurge_statuses,
+
+        ..Default::default()
+    }
+}
+
+pub fn target_reset_header(arn: &str) -> String {
+    format!("{RESERVED_METADATA_PREFIX_LOWER}{REPLICATION_RESET}-{arn}")
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct ResyncTargetDecision {
+    pub replicate: bool,
+    pub reset_id: String,
+    pub reset_before_date: Option<OffsetDateTime>,
+}
+
+/// ResyncDecision is a struct representing a map with target's individual resync decisions
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ResyncDecision {
+    pub targets: HashMap<String, ResyncTargetDecision>,
+}
+
+impl ResyncDecision {
+    pub fn new() -> Self {
+        Self { targets: HashMap::new() }
+    }
+
+    /// Returns true if no targets with resync decision present
+    pub fn is_empty(&self) -> bool {
+        self.targets.is_empty()
+    }
+
+    pub fn must_resync(&self) -> bool {
+        self.targets.values().any(|v| v.replicate)
+    }
+
+    pub fn must_resync_target(&self, tgt_arn: &str) -> bool {
+        self.targets.get(tgt_arn).map(|v| v.replicate).unwrap_or(false)
+    }
+}
+
+impl Default for ResyncDecision {
+    fn default() -> Self {
+        Self::new()
+    }
+}