Use failure for error management (#23)

* Use failure for error management.

Signed-off-by: Yilin Chen <[email protected]>

* Add error constructors

Signed-off-by: Yilin Chen <[email protected]>

* Remove NoSuchKey error

Signed-off-by: Yilin Chen <[email protected]>

Author: sticnarf

Cargo.toml

@@ -15,14 +15,14 @@ name = "tikv_client"
 futures = "0.1"
 serde = "1.0"
 serde_derive = "1.0"
-quick-error = "1.2"
 grpcio = { version = "0.4", features = [ "secure" ] }
 protobuf = "~2.0"
 tokio-core = "0.1"
 tokio-timer = "0.2"
 fxhash = "0.2"
 lazy_static = "0.2.1"
 log = "0.3.9"
+failure = "0.1"
 
 [dependencies.kvproto]
 git = "https://github.com/pingcap/kvproto.git"

examples/raw.rs

@@ -70,10 +70,8 @@ fn main() -> Result<()> {
         .expect("Could not delete value");
     println!("Key: {:?} deleted", key);
 
-    client
-        .get(key)
-        .wait()
-        .expect_err("Get returned value for not existing key");
+    // Get returns None for non-existing key
+    assert!(client.get(key).wait()?.is_none());
 
     let pairs: Vec<KvPair> = (1..3)
         .map(|i| KvPair::from((Key::from(format!("k{}", i)), Value::from(format!("v{}", i)))))

src/errors.rs

@@ -10,127 +10,245 @@
 // distributed under the License is distributed on an "AS IS" BASIS,
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
+use failure::{Backtrace, Context, Fail};
 use grpcio;
-use quick_error::quick_error;
-use std::{error, result};
-
-quick_error! {
-    /// An error originating from the TiKV client or dependencies.
-    ///
-    /// This client currently uses [`quick_error`](https://docs.rs/quick-error/1.2.2/quick_error/)
-    /// for errors. *This may change in future versions.*
-    #[derive(Debug)]
-    pub enum Error {
-        /// Wraps a `std::io::Error`.
-        Io(err: ::std::io::Error) {
-            from()
-            cause(err)
-            description(err.description())
-        }
-        /// Wraps a `grpcio::Error`.
-        Grpc(err: grpcio::Error) {
-            from()
-            cause(err)
-            description(err.description())
-        }
-        /// Represents that a futures oneshot channel was cancelled.
-        Canceled(err: ::futures::sync::oneshot::Canceled) {
-            from()
-            cause(err)
-            description(err.description())
-        }
-        /// An unknown error.
-        ///
-        /// Generally, this is not an expected error. Please report it if encountered.
-        Other(err: Box<error::Error + Sync + Send>) {
-            from()
-            cause(err.as_ref())
-            description(err.description())
-            display("unknown error {:?}", err)
-        }
-        /// A region was not found for the given key.
-        RegionForKeyNotFound(key: Vec<u8>) {
-            description("region is not found")
-            display("region is not found for key {:?}", key)
-        }
-        /// A region was not found.
-        RegionNotFound(region_id: u64, message: Option<String>) {
-            description("region is not found")
-            display("region {:?} is not found. {}", region_id, message.as_ref().unwrap_or(&"".to_owned()))
-        }
-        /// The peer is not a leader of the given region.
-        NotLeader(region_id: u64, message: Option<String>) {
-            description("peer is not leader")
-            display("peer is not leader for region {}. {}", region_id, message.as_ref().unwrap_or(&"".to_owned()))
-        }
-        /// The store does not match.
-        StoreNotMatch(request_store_id: u64, actual_store_id: u64, message: String) {
-            description("store not match")
-            display("requesting store '{}' when actual store is '{}'. {}", request_store_id, actual_store_id, message)
-        }
-        /// The given key is not within the given region.
-        KeyNotInRegion(key: Vec<u8>, region_id: u64, start_key: Vec<u8>, end_key: Vec<u8>) {
-            description("region is not found")
-            display("key {:?} is not in region {:?}: [{:?}, {:?})", key, region_id, start_key, end_key)
-        }
-        /// A stale epoch.
-        StaleEpoch(message: Option<String>) {
-            description("stale epoch")
-            display("{}", message.as_ref().unwrap_or(&"".to_owned()))
-        }
-        StaleCommand(message: String) {
-            description("stale command")
-            display("{}", message)
-        }
-        /// The server is too busy.
-        ServerIsBusy(reason: String, backoff: u64) {
-            description("server is busy")
-            display("server is busy: {:?}. Backoff {} ms", reason, backoff)
-        }
-        /// The given raft entry is too large for the region.
-        RaftEntryTooLarge(region_id: u64, entry_size: u64, message: String) {
-            description("raft entry too large")
-            display("{:?} bytes raft entry of region {:?} is too large. {}", entry_size, region_id, message)
-        }
-        KeyError(message: String) {
-            description("key error")
-            display("{}", message)
-        }
-        KVError(message: String) {
-            description("kv error")
-            display("{}", message)
-        }
-        InternalError(message: String) {
-           description("internal error")
-           display("{}", message)
-        }
-        InvalidKeyRange {
-            description("invalid key range")
-            display("Only left closed intervals are supported")
-        }
-        Unimplemented {
-            description("unimplemented feature")
-            display("Unimplemented feature")
-        }
-        EmptyValue {
-            description("can not set empty value")
-            display("Can not set empty value")
-        }
-        NoSuchKey {
-            description("key does not exist")
-            display("Key doest not exist")
-        }
-        InvalidOverlappingRanges {
-            description("ranges can not be overlapping")
-            display("Ranges can not be overlapping")
-        }
-        MaxScanLimitExceeded(limit: u32, max_limit: u32) {
-            description("limit exceeds max scan limit")
-            display("Limit {} excceds max scan limit {}", limit, max_limit)
+use std::fmt::{self, Display};
+use std::result;
+
+#[derive(Debug)]
+pub struct Error {
+    inner: Context<ErrorKind>,
+}
+
+/// An error originating from the TiKV client or dependencies.
+#[derive(Debug, Fail)]
+pub enum ErrorKind {
+    /// Wraps a `std::io::Error`.
+    #[fail(display = "IO error: {}", _0)]
+    Io(#[fail(cause)] std::io::Error),
+    /// Wraps a `grpcio::Error`.
+    #[fail(display = "gRPC error: {}", _0)]
+    Grpc(#[fail(cause)] grpcio::Error),
+    /// Represents that a futures oneshot channel was cancelled.
+    #[fail(display = "A futures oneshot channel was canceled. {}", _0)]
+    Canceled(#[fail(cause)] futures::sync::oneshot::Canceled),
+    /// Feature is not implemented.
+    #[fail(display = "Unimplemented feature")]
+    Unimplemented,
+    // No region is found for the given key.
+    #[fail(display = "Region is not found for key: {:?}", key)]
+    RegionForKeyNotFound { key: Vec<u8> },
+    /// The peer is not the leader for the region.
+    #[fail(display = "Peer is not leader for region {}. {}", region_id, message)]
+    NotLeader { region_id: u64, message: String },
+    /// Stale epoch
+    #[fail(display = "Stale epoch. {}", message)]
+    StaleEpoch { message: String },
+    /// No region is found for the given id.
+    #[fail(display = "Region {} is not found. {}", region_id, message)]
+    RegionNotFound { region_id: u64, message: String },
+    /// Invalid key range to scan. Only left bounded intervals are supported.
+    #[fail(display = "Only left bounded intervals are supported")]
+    InvalidKeyRange,
+    /// Cannot set an empty value
+    #[fail(display = "Cannot set an empty value")]
+    EmptyValue,
+    /// Scan limit exceeds the maximum
+    #[fail(display = "Limit {} exceeds max scan limit {}", limit, max_limit)]
+    MaxScanLimitExceeded { limit: u32, max_limit: u32 },
+    /// Wraps `kvproto::kvrpcpb::KeyError`
+    #[fail(display = "{:?}", _0)]
+    KeyError(kvproto::kvrpcpb::KeyError),
+    /// A string error returned by TiKV server
+    #[fail(display = "Kv error. {}", message)]
+    KvError { message: String },
+    /// Reconstructed `kvproto::errorpb::KeyNotInRegion`
+    #[fail(
+        display = "Key {:?} is not in region {}: [{:?}, {:?})",
+        key, region_id, start_key, end_key
+    )]
+    KeyNotInRegion {
+        key: Vec<u8>,
+        region_id: u64,
+        start_key: Vec<u8>,
+        end_key: Vec<u8>,
+    },
+    /// Reconstructed `kvproto::errorpb::ServerIsBusy`
+    #[fail(display = "Server is busy: {}. Backoff {} ms", reason, backoff_ms)]
+    ServerIsBusy { reason: String, backoff_ms: u64 },
+    /// Represents `kvproto::errorpb::StaleCommand` with additional error message
+    #[fail(display = "Stale command. {}", message)]
+    StaleCommand { message: String },
+    /// Represents `kvproto::errorpb::StoreNotMatch` with additional error message
+    #[fail(
+        display = "Requesting store {} when actual store is {}. {}",
+        request_store_id, actual_store_id, message
+    )]
+    StoreNotMatch {
+        request_store_id: u64,
+        actual_store_id: u64,
+        message: String,
+    },
+    /// Represents `kvproto::errorpb::RaftEntryTooLarge` with additional error message
+    #[fail(
+        display = "{} bytes raft entry of region {} is too large. {}",
+        entry_size, region_id, message
+    )]
+    RaftEntryTooLarge {
+        region_id: u64,
+        entry_size: u64,
+        message: String,
+    },
+    #[fail(display = "{}", message)]
+    InternalError { message: String },
+}
+
+impl Fail for Error {
+    fn cause(&self) -> Option<&Fail> {
+        self.inner.cause()
+    }
+
+    fn backtrace(&self) -> Option<&Backtrace> {
+        self.inner.backtrace()
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.inner, f)
+    }
+}
+
+impl Error {
+    pub fn kind(&self) -> &ErrorKind {
+        self.inner.get_context()
+    }
+
+    pub(crate) fn unimplemented() -> Self {
+        Error::from(ErrorKind::Unimplemented)
+    }
+
+    pub(crate) fn region_for_key_not_found(key: Vec<u8>) -> Self {
+        Error::from(ErrorKind::RegionForKeyNotFound { key })
+    }
+
+    pub(crate) fn not_leader(region_id: u64, message: Option<String>) -> Self {
+        Error::from(ErrorKind::NotLeader {
+            region_id,
+            message: message.unwrap_or_default(),
+        })
+    }
+
+    pub(crate) fn stale_epoch(message: Option<String>) -> Self {
+        Error::from(ErrorKind::StaleEpoch {
+            message: message.unwrap_or_default(),
+        })
+    }
+
+    pub(crate) fn region_not_found(region_id: u64, message: Option<String>) -> Self {
+        Error::from(ErrorKind::RegionNotFound {
+            region_id,
+            message: message.unwrap_or_default(),
+        })
+    }
+
+    pub(crate) fn invalid_key_range() -> Self {
+        Error::from(ErrorKind::InvalidKeyRange)
+    }
+
+    pub(crate) fn empty_value() -> Self {
+        Error::from(ErrorKind::EmptyValue)
+    }
+
+    pub(crate) fn max_scan_limit_exceeded(limit: u32, max_limit: u32) -> Self {
+        Error::from(ErrorKind::MaxScanLimitExceeded { limit, max_limit })
+    }
+
+    pub(crate) fn kv_error(message: String) -> Self {
+        Error::from(ErrorKind::KvError { message })
+    }
+
+    pub(crate) fn key_not_in_region(mut e: kvproto::errorpb::KeyNotInRegion) -> Self {
+        Error::from(ErrorKind::KeyNotInRegion {
+            key: e.take_key(),
+            region_id: e.get_region_id(),
+            start_key: e.take_start_key(),
+            end_key: e.take_end_key(),
+        })
+    }
+
+    pub(crate) fn server_is_busy(mut e: kvproto::errorpb::ServerIsBusy) -> Self {
+        Error::from(ErrorKind::ServerIsBusy {
+            reason: e.take_reason(),
+            backoff_ms: e.get_backoff_ms(),
+        })
+    }
+
+    pub(crate) fn stale_command(message: String) -> Self {
+        Error::from(ErrorKind::StaleCommand { message })
+    }
+
+    pub(crate) fn store_not_match(e: kvproto::errorpb::StoreNotMatch, message: String) -> Self {
+        Error::from(ErrorKind::StoreNotMatch {
+            request_store_id: e.get_request_store_id(),
+            actual_store_id: e.get_actual_store_id(),
+            message,
+        })
+    }
+
+    pub(crate) fn raft_entry_too_large(
+        e: kvproto::errorpb::RaftEntryTooLarge,
+        message: String,
+    ) -> Self {
+        Error::from(ErrorKind::RaftEntryTooLarge {
+            region_id: e.get_region_id(),
+            entry_size: e.get_entry_size(),
+            message,
+        })
+    }
+
+    pub(crate) fn internal_error(message: String) -> Self {
+        Error::from(ErrorKind::InternalError { message })
+    }
+}
+
+impl From<ErrorKind> for Error {
+    fn from(kind: ErrorKind) -> Error {
+        Error {
+            inner: Context::new(kind),
         }
     }
 }
 
+impl From<Context<ErrorKind>> for Error {
+    fn from(inner: Context<ErrorKind>) -> Error {
+        Error { inner }
+    }
+}
+
+impl From<std::io::Error> for Error {
+    fn from(err: std::io::Error) -> Self {
+        Error::from(ErrorKind::Io(err))
+    }
+}
+
+impl From<grpcio::Error> for Error {
+    fn from(err: grpcio::Error) -> Self {
+        Error::from(ErrorKind::Grpc(err))
+    }
+}
+
+impl From<futures::sync::oneshot::Canceled> for Error {
+    fn from(err: futures::sync::oneshot::Canceled) -> Self {
+        Error::from(ErrorKind::Canceled(err))
+    }
+}
+
+impl From<kvproto::kvrpcpb::KeyError> for Error {
+    fn from(err: kvproto::kvrpcpb::KeyError) -> Self {
+        Error::from(ErrorKind::KeyError(err))
+    }
+}
+
 /// A result holding an [`Error`](enum.Error.html).
 pub type Result<T> = result::Result<T, Error>;