Consolidate backends with their invokers

Author: nyurik

Cargo.toml

@@ -12,12 +12,16 @@ categories = ["science::geo"]
 
 [features]
 default = []
-http-async = ["dep:tokio", "dep:reqwest"]
-s3-async-native = ["dep:tokio", "dep:rust-s3", "rust-s3?/tokio-native-tls"]
-s3-async-rustls = ["dep:tokio", "dep:rust-s3", "rust-s3?/tokio-rustls-tls"]
-mmap-async-tokio = ["dep:tokio", "dep:fmmap", "fmmap?/tokio-async", "async-compression?/tokio"]
+http-async = ["__async", "dep:reqwest"]
+mmap-async-tokio = ["__async", "dep:fmmap", "fmmap?/tokio-async"]
+s3-async-native = ["__async-s3"]
+s3-async-rustls = ["__async-s3"]
 tilejson = ["dep:tilejson", "dep:serde", "dep:serde_json"]
 
+# Internal features, do not use
+__async = ["dep:tokio", "async-compression/tokio"]
+__async-s3 = ["__async", "dep:rust-s3", "rust-s3?/tokio-native-tls"]
+
 # TODO: support other async libraries
 
 [dependencies]

src/async_reader.rs

@@ -2,35 +2,14 @@
 //        so any file larger than 4GB, or an untrusted file with bad data may crash.
 #![allow(clippy::cast_possible_truncation)]
 
-#[cfg(feature = "mmap-async-tokio")]
-use std::path::Path;
-
 use async_recursion::async_recursion;
 use async_trait::async_trait;
 use bytes::Bytes;
-#[cfg(feature = "http-async")]
-use reqwest::{Client, IntoUrl};
-#[cfg(any(
-    feature = "http-async",
-    feature = "mmap-async-tokio",
-    feature = "s3-async-rustls",
-    feature = "s3-async-native"
-))]
+#[cfg(feature = "__async")]
 use tokio::io::AsyncReadExt;
 
-#[cfg(feature = "http-async")]
-use crate::backend::HttpBackend;
-#[cfg(feature = "mmap-async-tokio")]
-use crate::backend::MmapBackend;
-#[cfg(any(feature = "s3-async-rustls", feature = "s3-async-native"))]
-use crate::backend::S3Backend;
 use crate::cache::DirCacheResult;
-#[cfg(any(
-    feature = "http-async",
-    feature = "mmap-async-tokio",
-    feature = "s3-async-native",
-    feature = "s3-async-rustls"
-))]
+#[cfg(feature = "__async")]
 use crate::cache::{DirectoryCache, NoCache};
 use crate::directory::{DirEntry, Directory};
 use crate::error::{PmtError, PmtResult};
@@ -227,80 +206,6 @@ impl<B: AsyncBackend + Sync + Send, C: DirectoryCache + Sync + Send> AsyncPmTile
     }
 }
 
-#[cfg(feature = "http-async")]
-impl AsyncPmTilesReader<HttpBackend, NoCache> {
-    /// Creates a new `PMTiles` reader from a URL using the Reqwest backend.
-    ///
-    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
-    pub async fn new_with_url<U: IntoUrl>(client: Client, url: U) -> PmtResult<Self> {
-        Self::new_with_cached_url(NoCache, client, url).await
-    }
-}
-
-#[cfg(feature = "http-async")]
-impl<C: DirectoryCache + Sync + Send> AsyncPmTilesReader<HttpBackend, C> {
-    /// Creates a new `PMTiles` reader with cache from a URL using the Reqwest backend.
-    ///
-    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
-    pub async fn new_with_cached_url<U: IntoUrl>(
-        cache: C,
-        client: Client,
-        url: U,
-    ) -> PmtResult<Self> {
-        let backend = HttpBackend::try_from(client, url)?;
-
-        Self::try_from_cached_source(backend, cache).await
-    }
-}
-
-#[cfg(feature = "mmap-async-tokio")]
-impl AsyncPmTilesReader<MmapBackend, NoCache> {
-    /// Creates a new `PMTiles` reader from a file path using the async mmap backend.
-    ///
-    /// Fails if [p] does not exist or is an invalid archive.
-    pub async fn new_with_path<P: AsRef<Path>>(path: P) -> PmtResult<Self> {
-        Self::new_with_cached_path(NoCache, path).await
-    }
-}
-
-#[cfg(feature = "mmap-async-tokio")]
-impl<C: DirectoryCache + Sync + Send> AsyncPmTilesReader<MmapBackend, C> {
-    /// Creates a new cached `PMTiles` reader from a file path using the async mmap backend.
-    ///
-    /// Fails if [p] does not exist or is an invalid archive.
-    pub async fn new_with_cached_path<P: AsRef<Path>>(cache: C, path: P) -> PmtResult<Self> {
-        let backend = MmapBackend::try_from(path).await?;
-
-        Self::try_from_cached_source(backend, cache).await
-    }
-}
-
-#[cfg(any(feature = "s3-async-native", feature = "s3-async-rustls"))]
-impl AsyncPmTilesReader<S3Backend, NoCache> {
-    /// Creates a new `PMTiles` reader from a URL using the Reqwest backend.
-    ///
-    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
-    pub async fn new_with_bucket_path(bucket: s3::Bucket, path: String) -> PmtResult<Self> {
-        Self::new_with_cached_bucket_path(NoCache, bucket, path).await
-    }
-}
-
-#[cfg(any(feature = "s3-async-native", feature = "s3-async-rustls"))]
-impl<C: DirectoryCache + Sync + Send> AsyncPmTilesReader<S3Backend, C> {
-    /// Creates a new `PMTiles` reader with cache from a URL using the Reqwest backend.
-    ///
-    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
-    pub async fn new_with_cached_bucket_path(
-        cache: C,
-        bucket: s3::Bucket,
-        path: String,
-    ) -> PmtResult<Self> {
-        let backend = S3Backend::from(bucket, path);
-
-        Self::try_from_cached_source(backend, cache).await
-    }
-}
-
 #[async_trait]
 pub trait AsyncBackend {
     /// Reads exactly `length` bytes starting at `offset`
@@ -314,8 +219,8 @@ pub trait AsyncBackend {
 #[cfg(feature = "mmap-async-tokio")]
 mod tests {
     use super::AsyncPmTilesReader;
-    use crate::backend::MmapBackend;
     use crate::tests::{RASTER_FILE, VECTOR_FILE};
+    use crate::MmapBackend;
 
     #[tokio::test]
     async fn open_sanity_check() {

src/backend/mod.rs

@@ -3,10 +3,35 @@ use bytes::Bytes;
 use reqwest::header::{HeaderValue, RANGE};
 use reqwest::{Client, IntoUrl, Method, Request, StatusCode, Url};
 
-use crate::async_reader::AsyncBackend;
+use crate::async_reader::{AsyncBackend, AsyncPmTilesReader};
+use crate::cache::{DirectoryCache, NoCache};
 use crate::error::PmtResult;
 use crate::PmtError;
 
+impl AsyncPmTilesReader<HttpBackend, NoCache> {
+    /// Creates a new `PMTiles` reader from a URL using the Reqwest backend.
+    ///
+    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
+    pub async fn new_with_url<U: IntoUrl>(client: Client, url: U) -> PmtResult<Self> {
+        Self::new_with_cached_url(NoCache, client, url).await
+    }
+}
+
+impl<C: DirectoryCache + Sync + Send> AsyncPmTilesReader<HttpBackend, C> {
+    /// Creates a new `PMTiles` reader with cache from a URL using the Reqwest backend.
+    ///
+    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
+    pub async fn new_with_cached_url<U: IntoUrl>(
+        cache: C,
+        client: Client,
+        url: U,
+    ) -> PmtResult<Self> {
+        let backend = HttpBackend::try_from(client, url)?;
+
+        Self::try_from_cached_source(backend, cache).await
+    }
+}
+
 pub struct HttpBackend {
     client: Client,
     url: Url,

src/backend/s3.rs

@@ -5,9 +5,30 @@ use async_trait::async_trait;
 use bytes::{Buf, Bytes};
 use fmmap::tokio::{AsyncMmapFile, AsyncMmapFileExt as _, AsyncOptions};
 
-use crate::async_reader::AsyncBackend;
+use crate::async_reader::{AsyncBackend, AsyncPmTilesReader};
+use crate::cache::{DirectoryCache, NoCache};
 use crate::error::{PmtError, PmtResult};
 
+impl AsyncPmTilesReader<MmapBackend, NoCache> {
+    /// Creates a new `PMTiles` reader from a file path using the async mmap backend.
+    ///
+    /// Fails if [p] does not exist or is an invalid archive.
+    pub async fn new_with_path<P: AsRef<Path>>(path: P) -> PmtResult<Self> {
+        Self::new_with_cached_path(NoCache, path).await
+    }
+}
+
+impl<C: DirectoryCache + Sync + Send> AsyncPmTilesReader<MmapBackend, C> {
+    /// Creates a new cached `PMTiles` reader from a file path using the async mmap backend.
+    ///
+    /// Fails if [p] does not exist or is an invalid archive.
+    pub async fn new_with_cached_path<P: AsRef<Path>>(cache: C, path: P) -> PmtResult<Self> {
+        let backend = MmapBackend::try_from(path).await?;
+
+        Self::try_from_cached_source(backend, cache).await
+    }
+}
+
 pub struct MmapBackend {
     file: AsyncMmapFile,
 }

src/backend/http.rs renamed to src/backend_http.rs

@@ -0,0 +1,76 @@
+use async_trait::async_trait;
+use bytes::Bytes;
+use s3::Bucket;
+
+use crate::async_reader::{AsyncBackend, AsyncPmTilesReader};
+use crate::cache::{DirectoryCache, NoCache};
+use crate::error::PmtError::{ResponseBodyTooLong, UnexpectedNumberOfBytesReturned};
+use crate::PmtResult;
+
+impl AsyncPmTilesReader<S3Backend, NoCache> {
+    /// Creates a new `PMTiles` reader from a URL using the Reqwest backend.
+    ///
+    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
+    pub async fn new_with_bucket_path(bucket: Bucket, path: String) -> PmtResult<Self> {
+        Self::new_with_cached_bucket_path(NoCache, bucket, path).await
+    }
+}
+
+impl<C: DirectoryCache + Sync + Send> AsyncPmTilesReader<S3Backend, C> {
+    /// Creates a new `PMTiles` reader with cache from a URL using the Reqwest backend.
+    ///
+    /// Fails if [url] does not exist or is an invalid archive. (Note: HTTP requests are made to validate it.)
+    pub async fn new_with_cached_bucket_path(
+        cache: C,
+        bucket: Bucket,
+        path: String,
+    ) -> PmtResult<Self> {
+        let backend = S3Backend::from(bucket, path);
+
+        Self::try_from_cached_source(backend, cache).await
+    }
+}
+
+pub struct S3Backend {
+    bucket: Bucket,
+    path: String,
+}
+
+impl S3Backend {
+    #[must_use]
+    pub fn from(bucket: Bucket, path: String) -> S3Backend {
+        Self { bucket, path }
+    }
+}
+
+#[async_trait]
+impl AsyncBackend for S3Backend {
+    async fn read_exact(&self, offset: usize, length: usize) -> PmtResult<Bytes> {
+        let data = self.read(offset, length).await?;
+
+        if data.len() == length {
+            Ok(data)
+        } else {
+            Err(UnexpectedNumberOfBytesReturned(length, data.len()))
+        }
+    }
+
+    async fn read(&self, offset: usize, length: usize) -> PmtResult<Bytes> {
+        let response = self
+            .bucket
+            .get_object_range(
+                self.path.as_str(),
+                offset as _,
+                Some((offset + length - 1) as _),
+            )
+            .await?;
+
+        let response_bytes = response.bytes();
+
+        if response_bytes.len() > length {
+            Err(ResponseBodyTooLong(response_bytes.len(), length))
+        } else {
+            Ok(response_bytes.clone())
+        }
+    }
+}

src/backend/mmap.rs renamed to src/backend_mmap.rs

@@ -29,21 +29,13 @@ pub enum PmtError {
     #[cfg(feature = "mmap-async-tokio")]
     #[error("Unable to open mmap file")]
     UnableToOpenMmapFile,
-    #[cfg(any(
-        feature = "http-async",
-        feature = "s3-async-native",
-        feature = "s3-async-rustls"
-    ))]
+    #[cfg(any(feature = "http-async", feature = "__async-s3"))]
     #[error("Unexpected number of bytes returned [expected: {0}, received: {1}].")]
     UnexpectedNumberOfBytesReturned(usize, usize),
     #[cfg(feature = "http-async")]
     #[error("Range requests unsupported")]
     RangeRequestsUnsupported,
-    #[cfg(any(
-        feature = "http-async",
-        feature = "s3-async-native",
-        feature = "s3-async-rustls"
-    ))]
+    #[cfg(any(feature = "http-async", feature = "__async-s3"))]
     #[error("HTTP response body is too long, Response {0}B > requested {1}B")]
     ResponseBodyTooLong(usize, usize),
     #[cfg(feature = "http-async")]
@@ -52,7 +44,7 @@ pub enum PmtError {
     #[cfg(feature = "http-async")]
     #[error(transparent)]
     InvalidHeaderValue(#[from] reqwest::header::InvalidHeaderValue),
-    #[cfg(any(feature = "s3-async-rustls", feature = "s3-async-native"))]
+    #[cfg(feature = "__async-s3")]
     #[error(transparent)]
     S3(#[from] s3::error::S3Error),
 }