Add ObjectStoreScheme (apache#4047)

object_store/src/lib.rs

@@ -249,8 +249,11 @@ pub use client::{backoff::BackoffConfig, retry::RetryConfig};
 
 #[cfg(any(feature = "azure", feature = "aws", feature = "gcp"))]
 mod multipart;
+mod scheme;
 mod util;
 
+pub use scheme::ObjectStoreScheme;
+
 use crate::path::Path;
 #[cfg(not(target_arch = "wasm32"))]
 use crate::util::maybe_spawn_blocking;

object_store/src/scheme.rs

@@ -0,0 +1,114 @@
+use crate::{Error, Result};
+use url::Url;
+
+/// Recognises various URL formats, identifying the relevant [`ObjectStore`](crate::ObjectStore)
+///
+/// This can be combined with the [with_url](crate::aws::AmazonS3Builder::with_url) methods
+/// on the corresponding builder to construct the relevant type of store
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+#[non_exhaustive]
+pub enum ObjectStoreScheme {
+    /// Url corresponding to [`LocalFileSystem`](crate::local::LocalFileSystem)
+    Local,
+    /// Url corresponding to [`InMemory`](crate::memory::InMemory)
+    Memory,
+    /// Url corresponding to [`AmazonS3`](crate::aws::AmazonS3)
+    AmazonS3,
+    /// Url corresponding to [`GoogleCloudStorage`](crate::gcp::GoogleCloudStorage)
+    GoogleCloudStorage,
+    /// Url corresponding to [`MicrosoftAzure`](crate::azure::MicrosoftAzure)
+    MicrosoftAzure,
+    /// Url corresponding to [`HttpStore`](crate::http::HttpStore)
+    Http,
+}
+
+impl ObjectStoreScheme {
+    /// Create an [`ObjectStoreScheme`] from the provided [`Url`]
+    pub fn try_new(url: &Url) -> Result<Self> {
+        match (url.scheme(), url.host_str()) {
+            ("file", None) => Ok(Self::Local),
+            ("memory", None) => Ok(Self::Memory),
+            ("s3" | "s3a", Some(_)) => Ok(Self::AmazonS3),
+            ("gs", Some(_)) => Ok(Self::GoogleCloudStorage),
+            ("az" | "adl" | "azure" | "abfs" | "abfss", Some(_)) => {
+                Ok(Self::MicrosoftAzure)
+            }
+            ("http", Some(_)) => Ok(Self::Http),
+            ("https", Some(host)) => {
+                if host.ends_with("dfs.core.windows.net") {
+                    Ok(Self::MicrosoftAzure)
+                } else if host.ends_with("blob.core.windows.net") {
+                    Ok(Self::MicrosoftAzure)
+                } else if host.ends_with("amazonaws.com") {
+                    Ok(Self::AmazonS3)
+                } else {
+                    Ok(Self::Http)
+                }
+            }
+            _ => Err(Error::Generic {
+                store: "ObjectStoreScheme",
+                source: format!("Unrecognized URL: {url}").into(),
+            }),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_scheme() {
+        let cases = [
+            ("file:/path", ObjectStoreScheme::Local),
+            ("file:///path", ObjectStoreScheme::Local),
+            ("memory:/foo", ObjectStoreScheme::Memory),
+            ("memory:///", ObjectStoreScheme::Memory),
+            ("s3://bucket/path", ObjectStoreScheme::AmazonS3),
+            ("s3a://bucket/path", ObjectStoreScheme::AmazonS3),
+            (
+                "https://s3.bucket.amazonaws.com",
+                ObjectStoreScheme::AmazonS3,
+            ),
+            (
+                "https://bucket.s3.region.amazonaws.com",
+                ObjectStoreScheme::AmazonS3,
+            ),
+            ("abfs://container/path", ObjectStoreScheme::MicrosoftAzure),
+            (
+                "abfs://file_system@account_name.dfs.core.windows.net/path",
+                ObjectStoreScheme::MicrosoftAzure,
+            ),
+            (
+                "abfss://file_system@account_name.dfs.core.windows.net/path",
+                ObjectStoreScheme::MicrosoftAzure,
+            ),
+            (
+                "https://account.dfs.core.windows.net",
+                ObjectStoreScheme::MicrosoftAzure,
+            ),
+            (
+                "https://account.blob.core.windows.net",
+                ObjectStoreScheme::MicrosoftAzure,
+            ),
+            ("gs://bucket/path", ObjectStoreScheme::GoogleCloudStorage),
+            ("http://mydomain/path", ObjectStoreScheme::Http),
+            ("https://mydomain/path", ObjectStoreScheme::Http),
+        ];
+
+        for (s, expected) in cases {
+            let url = Url::parse(s).unwrap();
+            assert_eq!(ObjectStoreScheme::try_new(&url).unwrap(), expected);
+        }
+
+        let neg_cases = [
+            "unix:/run/foo.socket",
+            "file://remote/path",
+            "memory://remote/",
+        ];
+        for s in neg_cases {
+            let url = Url::parse(s).unwrap();
+            assert!(ObjectStoreScheme::try_new(&url).is_err());
+        }
+    }
+}