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authorAlex <alex@adnab.me>2022-05-10 13:16:57 +0200
committerAlex <alex@adnab.me>2022-05-10 13:16:57 +0200
commit5768bf362262f78376af14517c4921941986192e (patch)
treeb4baf3051eade0f63649443278bb3a3f4c38ec25 /src/api/router_macros.rs
parentdef78c5e6f5da37a0d17b5652c525fbeccbc2e86 (diff)
downloadgarage-5768bf362262f78376af14517c4921941986192e.tar.gz
garage-5768bf362262f78376af14517c4921941986192e.zip
First implementation of K2V (#293)
**Specification:** View spec at [this URL](https://git.deuxfleurs.fr/Deuxfleurs/garage/src/branch/k2v/doc/drafts/k2v-spec.md) - [x] Specify the structure of K2V triples - [x] Specify the DVVS format used for causality detection - [x] Specify the K2V index (just a counter of number of values per partition key) - [x] Specify single-item endpoints: ReadItem, InsertItem, DeleteItem - [x] Specify index endpoint: ReadIndex - [x] Specify multi-item endpoints: InsertBatch, ReadBatch, DeleteBatch - [x] Move to JSON objects instead of tuples - [x] Specify endpoints for polling for updates on single values (PollItem) **Implementation:** - [x] Table for K2V items, causal contexts - [x] Indexing mechanism and table for K2V index - [x] Make API handlers a bit more generic - [x] K2V API endpoint - [x] K2V API router - [x] ReadItem - [x] InsertItem - [x] DeleteItem - [x] PollItem - [x] ReadIndex - [x] InsertBatch - [x] ReadBatch - [x] DeleteBatch **Testing:** - [x] Just a simple Python script that does some requests to check visually that things are going right (does not contain parsing of results or assertions on returned values) - [x] Actual tests: - [x] Adapt testing framework - [x] Simple test with InsertItem + ReadItem - [x] Test with several Insert/Read/DeleteItem + ReadIndex - [x] Test all combinations of return formats for ReadItem - [x] Test with ReadBatch, InsertBatch, DeleteBatch - [x] Test with PollItem - [x] Test error codes - [ ] Fix most broken stuff - [x] test PollItem broken randomly - [x] when invalid causality tokens are given, errors should be 4xx not 5xx **Improvements:** - [x] Descending range queries - [x] Specify - [x] Implement - [x] Add test - [x] Batch updates to index counter - [x] Put K2V behind `k2v` feature flag Co-authored-by: Alex Auvolat <alex@adnab.me> Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/293 Co-authored-by: Alex <alex@adnab.me> Co-committed-by: Alex <alex@adnab.me>
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+/// This macro is used to generate very repetitive match {} blocks in this module
+/// It is _not_ made to be used anywhere else
+macro_rules! router_match {
+ (@match $enum:expr , [ $($endpoint:ident,)* ]) => {{
+ // usage: router_match {@match my_enum, [ VariantWithField1, VariantWithField2 ..] }
+ // returns true if the variant was one of the listed variants, false otherwise.
+ use Endpoint::*;
+ match $enum {
+ $(
+ $endpoint { .. } => true,
+ )*
+ _ => false
+ }
+ }};
+ (@extract $enum:expr , $param:ident, [ $($endpoint:ident,)* ]) => {{
+ // usage: router_match {@extract my_enum, field_name, [ VariantWithField1, VariantWithField2 ..] }
+ // returns Some(field_value), or None if the variant was not one of the listed variants.
+ use Endpoint::*;
+ match $enum {
+ $(
+ $endpoint {$param, ..} => Some($param),
+ )*
+ _ => None
+ }
+ }};
+ (@gen_parser ($keyword:expr, $key:ident, $query:expr, $header:expr),
+ key: [$($kw_k:ident $(if $required_k:ident)? $(header $header_k:expr)? => $api_k:ident $(($($conv_k:ident :: $param_k:ident),*))?,)*],
+ no_key: [$($kw_nk:ident $(if $required_nk:ident)? $(if_header $header_nk:expr)? => $api_nk:ident $(($($conv_nk:ident :: $param_nk:ident),*))?,)*]) => {{
+ // usage: router_match {@gen_parser (keyword, key, query, header),
+ // key: [
+ // SOME_KEYWORD => VariantWithKey,
+ // ...
+ // ],
+ // no_key: [
+ // SOME_KEYWORD => VariantWithoutKey,
+ // ...
+ // ]
+ // }
+ // See in from_{method} for more detailed usage.
+ use Endpoint::*;
+ use keywords::*;
+ match ($keyword, !$key.is_empty()){
+ $(
+ ($kw_k, true) if true $(&& $query.$required_k.is_some())? $(&& $header.contains_key($header_k))? => Ok($api_k {
+ $key,
+ $($(
+ $param_k: router_match!(@@parse_param $query, $conv_k, $param_k),
+ )*)?
+ }),
+ )*
+ $(
+ ($kw_nk, false) $(if $query.$required_nk.is_some())? $(if $header.contains($header_nk))? => Ok($api_nk {
+ $($(
+ $param_nk: router_match!(@@parse_param $query, $conv_nk, $param_nk),
+ )*)?
+ }),
+ )*
+ (kw, _) => Err(Error::BadRequest(format!("Invalid endpoint: {}", kw)))
+ }
+ }};
+
+ (@@parse_param $query:expr, query_opt, $param:ident) => {{
+ // extract optional query parameter
+ $query.$param.take().map(|param| param.into_owned())
+ }};
+ (@@parse_param $query:expr, query, $param:ident) => {{
+ // extract mendatory query parameter
+ $query.$param.take().ok_or_bad_request("Missing argument for endpoint")?.into_owned()
+ }};
+ (@@parse_param $query:expr, opt_parse, $param:ident) => {{
+ // extract and parse optional query parameter
+ // missing parameter is file, however parse error is reported as an error
+ $query.$param
+ .take()
+ .map(|param| param.parse())
+ .transpose()
+ .map_err(|_| Error::BadRequest("Failed to parse query parameter".to_owned()))?
+ }};
+ (@@parse_param $query:expr, parse, $param:ident) => {{
+ // extract and parse mandatory query parameter
+ // both missing and un-parseable parameters are reported as errors
+ $query.$param.take().ok_or_bad_request("Missing argument for endpoint")?
+ .parse()
+ .map_err(|_| Error::BadRequest("Failed to parse query parameter".to_owned()))?
+ }};
+ (@func
+ $(#[$doc:meta])*
+ pub enum Endpoint {
+ $(
+ $(#[$outer:meta])*
+ $variant:ident $({
+ $($name:ident: $ty:ty,)*
+ })?,
+ )*
+ }) => {
+ $(#[$doc])*
+ pub enum Endpoint {
+ $(
+ $(#[$outer])*
+ $variant $({
+ $($name: $ty, )*
+ })?,
+ )*
+ }
+ impl Endpoint {
+ pub fn name(&self) -> &'static str {
+ match self {
+ $(Endpoint::$variant $({ $($name: _,)* .. })? => stringify!($variant),)*
+ }
+ }
+ }
+ };
+ (@if ($($cond:tt)+) then ($($then:tt)*) else ($($else:tt)*)) => {
+ $($then)*
+ };
+ (@if () then ($($then:tt)*) else ($($else:tt)*)) => {
+ $($else)*
+ };
+}
+
+/// This macro is used to generate part of the code in this module. It must be called only one, and
+/// is useless outside of this module.
+macro_rules! generateQueryParameters {
+ ( $($rest:expr => $name:ident),* ) => {
+ /// Struct containing all query parameters used in endpoints. Think of it as an HashMap,
+ /// but with keys statically known.
+ #[derive(Debug, Default)]
+ struct QueryParameters<'a> {
+ keyword: Option<Cow<'a, str>>,
+ $(
+ $name: Option<Cow<'a, str>>,
+ )*
+ }
+
+ impl<'a> QueryParameters<'a> {
+ /// Build this struct from the query part of an URI.
+ fn from_query(query: &'a str) -> Result<Self, Error> {
+ let mut res: Self = Default::default();
+ for (k, v) in url::form_urlencoded::parse(query.as_bytes()) {
+ let repeated = match k.as_ref() {
+ $(
+ $rest => if !v.is_empty() {
+ res.$name.replace(v).is_some()
+ } else {
+ false
+ },
+ )*
+ _ => {
+ if k.starts_with("response-") || k.starts_with("X-Amz-") {
+ false
+ } else if v.as_ref().is_empty() {
+ if res.keyword.replace(k).is_some() {
+ return Err(Error::BadRequest("Multiple keywords".to_owned()));
+ }
+ continue;
+ } else {
+ debug!("Received an unknown query parameter: '{}'", k);
+ false
+ }
+ }
+ };
+ if repeated {
+ return Err(Error::BadRequest(format!(
+ "Query parameter repeated: '{}'",
+ k
+ )));
+ }
+ }
+ Ok(res)
+ }
+
+ /// Get an error message in case not all parameters where used when extracting them to
+ /// build an Enpoint variant
+ fn nonempty_message(&self) -> Option<&str> {
+ if self.keyword.is_some() {
+ Some("Keyword not used")
+ } $(
+ else if self.$name.is_some() {
+ Some(concat!("'", $rest, "'"))
+ }
+ )* else {
+ None
+ }
+ }
+ }
+ }
+}
+
+pub(crate) use generateQueryParameters;
+pub(crate) use router_match;