grafbase_sdk/host_io/grpc.rs
1//! Generic gRPC client.
2
3use crate::wit;
4
5/// A successful response from a unary gRPC call.
6#[derive(Debug)]
7pub struct GrpcUnaryResponse {
8 inner: wit::GrpcUnaryResponse,
9}
10
11impl GrpcUnaryResponse {
12 /// The response body.
13 pub fn message(&self) -> &[u8] {
14 &self.inner.message
15 }
16
17 /// Return the response body, consuming self.
18 pub fn into_message(self) -> Vec<u8> {
19 self.inner.message
20 }
21
22 /// The response metadata.
23 pub fn metadata(&self) -> &[(String, Vec<u8>)] {
24 &self.inner.metadata
25 }
26}
27
28/// A response stream from a server streaming gRPC call.
29#[derive(Debug)]
30pub struct GrpcStreamingResponse {
31 inner: wit::GrpcStreamingResponse,
32}
33
34impl GrpcStreamingResponse {
35 /// Get the next message in the stream. `None` means the stream has ended and there will no longer be any messages.
36 pub fn next_message(&self) -> Result<Option<Vec<u8>>, GrpcStatus> {
37 self.inner.get_next_message().map_err(|inner| GrpcStatus { inner })
38 }
39
40 /// The response metadata.
41 pub fn metadata(&self) -> Vec<(String, Vec<u8>)> {
42 self.inner.get_metadata()
43 }
44}
45
46/// An error response from a unary gRPC call.
47#[derive(Debug)]
48pub struct GrpcStatus {
49 inner: wit::GrpcStatus,
50}
51
52impl GrpcStatus {
53 /// The grpc status code of the response.
54 pub fn code(&self) -> GrpcStatusCode {
55 self.inner.code.into()
56 }
57
58 /// The error message of the response.
59 pub fn message(&self) -> &str {
60 &self.inner.message
61 }
62
63 /// The metadata of the response.
64 pub fn metadata(&self) -> &[(String, Vec<u8>)] {
65 &self.inner.metadata
66 }
67}
68
69/// A gRPC client connected to a single endpoint.
70#[derive(Debug)]
71pub struct GrpcClient {
72 inner: wit::GrpcClient,
73}
74
75impl GrpcClient {
76 /// Construct a new gRPC client.
77 pub fn new(endpoint: &str) -> Result<Self, crate::types::Error> {
78 Ok(Self {
79 inner: wit::GrpcClient::new(&wit::GrpcClientConfiguration {
80 uri: endpoint.to_owned(),
81 })?,
82 })
83 }
84
85 /// Make a unary RPC call. The method can be client streaming, but only the provided message will be sent.
86 pub fn unary(
87 &self,
88 message: &[u8],
89 service: &str,
90 method: &str,
91 metadata: &[(String, Vec<u8>)],
92 timeout: Option<std::time::Duration>,
93 ) -> Result<GrpcUnaryResponse, GrpcStatus> {
94 self.inner
95 .unary(
96 message,
97 service,
98 method,
99 metadata,
100 timeout.map(|duration| duration.as_millis() as u64),
101 )
102 .map(|response| GrpcUnaryResponse { inner: response })
103 .map_err(|error| GrpcStatus { inner: error })
104 }
105
106 /// Make a server-streaming RPC call. The method can be client streaming, but only the single message provided will be sent.
107 pub fn streaming(
108 &self,
109 message: &[u8],
110 service: &str,
111 method: &str,
112 metadata: &[(String, Vec<u8>)],
113 timeout: Option<std::time::Duration>,
114 ) -> Result<GrpcStreamingResponse, GrpcStatus> {
115 self.inner
116 .streaming(
117 message,
118 service,
119 method,
120 metadata,
121 timeout.map(|duration| duration.as_millis() as u64),
122 )
123 .map(|response| GrpcStreamingResponse { inner: response })
124 .map_err(|error| GrpcStatus { inner: error })
125 }
126}
127
128/// Response status of gRPC requests.
129///
130/// Reference: <https://github.com/grpc/grpc/blob/master/doc/statuscodes.md#status-codes-and-their-use-in-grpc>
131#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
132pub enum GrpcStatusCode {
133 /// 0. Not an error; returned on success.
134 Ok,
135 /// 1. The operation was cancelled, typically by the caller.
136 Cancelled,
137 /// 2. Unknown error. For example, this error may be returned when a Status value received from another address space belongs to an error space that is not known in this address space. Also errors raised by APIs that do not return enough error information may be converted to this error.
138 Unknown,
139 /// 3. The client specified an invalid argument. Note that this differs from FAILED_PRECONDITION. INVALID_ARGUMENT indicates arguments that are problematic regardless of the state of the system (e.g., a malformed file name).
140 InvalidArgument,
141 /// 4. The deadline expired before the operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully. For example, a successful response from a server could have been delayed long
142 DeadlineExceeded,
143 /// 5. Some requested entity (e.g., file or directory) was not found. Note to server developers: if a request is denied for an entire class of users, such as gradual feature rollout or undocumented allowlist, NOT_FOUND may be used. If a request is denied for some users within a class of users, such as user-based access control, PERMISSION_DENIED must be used.
144 NotFound,
145 /// 6. The entity that a client attempted to create (e.g., file or directory) already exists.
146 AlreadyExists,
147 /// 7. The caller does not have permission to execute the specified operation. PERMISSION_DENIED must not be used for rejections caused by exhausting some resource (use RESOURCE_EXHAUSTED instead for those errors). PERMISSION_DENIED must not be used if the caller can not be identified (use UNAUTHENTICATED instead for those errors). This error code does not imply the request is valid or the requested entity exists or satisfies other pre-conditions.
148 PermissionDenied,
149 /// 8. Some resource has been exhausted, perhaps a per-user quota, or perhaps the entire file system is out of space.
150 ResourceExhausted,
151 /// 9. The operation was rejected because the system is not in a state required for the operation's execution. For example, the directory to be deleted is non-empty, an rmdir operation is applied to a non-directory, etc. Service implementors can use the following guidelines to decide between FAILED_PRECONDITION, ABORTED, and UNAVAILABLE: (a) Use UNAVAILABLE if the client can retry just the failing call. (b) Use ABORTED if the client should retry at a higher level (e.g., when a client-specified test-and-set fails, indicating the client should restart a read-modify-write sequence). (c) Use FAILED_PRECONDITION if the client should not retry until the system state has been explicitly fixed. E.g., if an "rmdir" fails because the directory is non-empty, FAILED_PRECONDITION should be returned since the client should not retry unless the files are deleted from the directory.
152 FailedPrecondition,
153 /// 10. The operation was aborted, typically due to a concurrency issue such as a sequencer check failure or transaction abort. See the guidelines above for deciding between FAILED_PRECONDITION, ABORTED, and UNAVAILABLE.
154 Aborted,
155 /// 11. The operation was attempted past the valid range. E.g., seeking or reading past end-of-file. Unlike INVALID_ARGUMENT, this error indicates a problem that may be fixed if the system state changes. For example, a 32-bit file system will generate INVALID_ARGUMENT if asked to read at an offset that is not in the range [0,2^32-1], but it will generate OUT_OF_RANGE if asked to read from an offset past the current file size. There is a fair bit of overlap between FAILED_PRECONDITION and OUT_OF_RANGE. We recommend using OUT_OF_RANGE (the more specific error) when it applies so that callers who are iterating through a space can easily look for an OUT_OF_RANGE error to detect when they are done.
156 OutOfRange,
157 /// 12. The operation is not implemented or is not supported/enabled in this service.
158 Unimplemented,
159 /// 13. Internal errors. This means that some invariants expected by the underlying system have been broken. This error code is reserved for serious errors.
160 Internal,
161 /// 14. The service is currently unavailable. This is most likely a transient condition, which can be corrected by retrying with a backoff. Note that it is not always safe to retry non-idempotent operations.
162 Unavailable,
163 /// 15. Unrecoverable data loss or corruption.
164 DataLoss,
165 /// 16. The request does not have valid authentication credentials for the operation.
166 Unauthenticated,
167}
168
169impl From<wit::GrpcStatusCode> for GrpcStatusCode {
170 fn from(value: wit::GrpcStatusCode) -> Self {
171 match value {
172 wit::GrpcStatusCode::Ok => GrpcStatusCode::Ok,
173 wit::GrpcStatusCode::Cancelled => GrpcStatusCode::Cancelled,
174 wit::GrpcStatusCode::Unknown => GrpcStatusCode::Unknown,
175 wit::GrpcStatusCode::InvalidArgument => GrpcStatusCode::InvalidArgument,
176 wit::GrpcStatusCode::DeadlineExceeded => GrpcStatusCode::DeadlineExceeded,
177 wit::GrpcStatusCode::NotFound => GrpcStatusCode::NotFound,
178 wit::GrpcStatusCode::AlreadyExists => GrpcStatusCode::AlreadyExists,
179 wit::GrpcStatusCode::PermissionDenied => GrpcStatusCode::PermissionDenied,
180 wit::GrpcStatusCode::ResourceExhausted => GrpcStatusCode::ResourceExhausted,
181 wit::GrpcStatusCode::FailedPrecondition => GrpcStatusCode::FailedPrecondition,
182 wit::GrpcStatusCode::Aborted => GrpcStatusCode::Aborted,
183 wit::GrpcStatusCode::OutOfRange => GrpcStatusCode::OutOfRange,
184 wit::GrpcStatusCode::Unimplemented => GrpcStatusCode::Unimplemented,
185 wit::GrpcStatusCode::Internal => GrpcStatusCode::Internal,
186 wit::GrpcStatusCode::Unavailable => GrpcStatusCode::Unavailable,
187 wit::GrpcStatusCode::DataLoss => GrpcStatusCode::DataLoss,
188 wit::GrpcStatusCode::Unauthenticated => GrpcStatusCode::Unauthenticated,
189 }
190 }
191}