todo: quorum err check

ecstore/src/lib.rs

@@ -7,6 +7,7 @@ mod erasure;
 pub mod error;
 mod file_meta;
 mod peer;
+mod quorum;
 pub mod set_disk;
 mod sets;
 pub mod store;

ecstore/src/quorum.rs

@@ -0,0 +1,90 @@
+use crate::{disk::error::DiskError, error::Error};
+use std::collections::HashMap;
+
+type CheckErrorFn = fn(e: &Error) -> bool;
+
+#[derive(Debug, thiserror::Error)]
+enum QuorumError {
+    #[error("Read quorum not met")]
+    Read,
+    #[error("disk not found")]
+    Write,
+}
+
+fn is_file_not_found(e: &Error) -> bool {
+    DiskError::FileNotFound.is(e)
+}
+
+// 用于检查错误是否被忽略的函数
+fn is_err_ignored(err: &Error, ignored_errs: &[CheckErrorFn]) -> bool {
+    ignored_errs.iter().any(|&ignored_err| ignored_err(err))
+}
+
+// 减少错误数量并返回出现次数最多的错误
+fn reduce_errs(errs: &Vec<Option<Error>>, ignored_errs: &[CheckErrorFn]) -> (usize, Option<Error>) {
+    let mut error_counts: HashMap<String, usize> = HashMap::new();
+    let mut error_map: HashMap<String, &Error> = HashMap::new();
+    let nil = "nil".to_string();
+    for operr in errs.iter() {
+        if operr.is_none() {
+            *error_counts.entry(nil.clone()).or_insert(0) += 1;
+            continue;
+        }
+
+        let err = operr.as_ref().unwrap();
+
+        if is_err_ignored(err, &ignored_errs) {
+            continue;
+        }
+
+        let errstr = err.to_string();
+
+        *error_map.entry(errstr.clone()).or_insert(err);
+        *error_counts.entry(errstr.clone()).or_insert(0) += 1;
+    }
+
+    let mut max = 0;
+    let mut max_err = nil.clone();
+    for (&ref err, &count) in error_counts.iter() {
+        if count > max || (count == max && *err == nil) {
+            max = count;
+            max_err = err.clone();
+        }
+    }
+
+    if let Some(c) = error_counts.get(&max_err) {
+        if let Some(&err) = error_map.get(&max_err) {
+            // return (*c, Some(err.clone()));
+            return (*c, None);
+        }
+
+        return (*c, None);
+    }
+
+    (0, None)
+}
+
+// 根据quorum验证错误数量
+fn reduce_quorum_errs<'a>(
+    errs: &'a Vec<Option<Error>>,
+    ignored_errs: &[CheckErrorFn],
+    quorum: usize,
+    quorum_err: Error,
+) -> Option<Error> {
+    let (max_count, max_err) = reduce_errs(errs, ignored_errs);
+    if max_count >= quorum {
+        max_err
+    } else {
+        Some(quorum_err)
+    }
+}
+
+// 根据读quorum验证错误数量
+fn reduce_read_quorum_errs(errs: &Vec<Option<Error>>, ignored_errs: &[CheckErrorFn], read_quorum: usize) -> Option<Error> {
+    reduce_quorum_errs(errs, ignored_errs, read_quorum, Error::new(QuorumError::Read))
+}
+
+// 根据写quorum验证错误数量
+fn reduce_write_quorum_errs(errs: &Vec<Option<Error>>, ignored_errs: &[CheckErrorFn], write_quorum: usize) -> Option<Error> {
+    reduce_quorum_errs(errs, ignored_errs, write_quorum, Error::new(QuorumError::Write))
+}