add metadata method

Author: samtkaplan

Project.toml

@@ -1,6 +1,6 @@
 name = "AzStorage"
 uuid = "c6697862-1611-5eae-9ef8-48803c85c8d6"
-version = "2.9.3"
+version = "2.10.0"
 
 [deps]
 AbstractStorage = "14dbef02-f468-5f15-853e-5ec8dee7b899"

src/AzStorage.jl

@@ -1335,6 +1335,49 @@ Returns the size of the blob corresponding to `object::AzObject`
 """
 Base.filesize(o::AzObject) = filesize(o.container, o.name)
 
+"""
+    metadata(container, "blobname")
+
+Returns a dictionary corresponding to the metadata of the blob "blobname" in `container::AzContainer`.  The dictionary contains the following keys:
+
+* "size": The size of the blob in bytes.
+* "modified": The last modified date of the blob.
+* "created": The creation date of the blob.
+* "accessed": The last access date of the blob.
+"""
+function metadata(c::AzContainer, o::AbstractString)
+    r = @retry c.nretry HTTP.request(
+        "HEAD",
+        "https://$(c.storageaccount).blob.core.windows.net/$(c.containername)/$(addprefix(c,o))",
+        [
+            "Authorization" => "Bearer $(token(c.session))",
+            "x-ms-version" => API_VERSION
+        ],
+        retry = false,
+        verbose = c.verbose,
+        connect_timeout = c.connect_timeout,
+        readtimeout = c.read_timeout)
+
+    Dict(
+        "size" => parse(Int, HTTP.header(r, "Content-Length", "0")),
+        "modified" => tryparse(DateTime, HTTP.header(r, "Last-Modified", "not a date"), dateformat"e, dd u yyyy HH:MM:SS \G\M\T"),
+        "created" => tryparse(DateTime, HTTP.header(r, "x-ms-creation-time", "not a date"), dateformat"e, dd u yyyy HH:MM:SS \G\M\T"),
+        "accessed" => tryparse(DateTime, HTTP.header(r, "x-ms-last-access-time", "not a date"), dateformat"e, dd u yyyy HH:MM:SS \G\M\T")
+    )
+end
+
+"""
+    metadata(object::AzObject)
+
+Returns a dictionary corresponding to the metadata of the blob corresponding to `object::AzObject`.  The dictionary contains the following keys:
+
+* "size": The size of the blob in bytes.
+* "modified": The last modified date of the blob.
+* "created": The creation date of the blob.
+* "accessed": The last access date of the blob.
+"""
+metadata(o::AzObject) = metadata(o.container, o.name)
+
 """
     rm(container, "blobname")
 
@@ -1540,6 +1583,6 @@ Returns the access tier for a blob `o::AzObject`.
 """
 tier(o::AzObject) = tier(o.container, o.name)
 
-export AzContainer, containers, readdlm, status, tier, tier!, writedlm
+export AzContainer, containers, metadata, readdlm, status, tier, tier!, writedlm
 
 end

test/runtests.jl

@@ -220,6 +220,21 @@ end
     rm(c)
 end
 
+@testset "Containers, metadata, prefix=$prefix" for prefix in ("", "prefix")
+    suffix = prefix == "" ? "-foo" : "-bar"
+    r = uuid4()
+    c = AzContainer("foo-$r-f$suffix", prefix=prefix, storageaccount=storageaccount, session=session)
+    c = robust_mkpath(c)
+
+    write(c, "bar", rand(UInt8,10))
+
+    m = metadata(c, "bar")
+    @test m["size"] == 10
+    @test isa(m["created"], DateTime)
+    @test isa(m["modified"], DateTime) || isa(m["modified"], Nothing)
+    @test isa(m["accessed"], DateTime) || isa(m["accessed"], Nothing)
+end
+
 @testset "Containers, bytes, nthreads=$nthreads, prefix=$prefix" for nthreads in (1, 2), prefix in ("","prefix")
     suffix = prefix == "" ? "-foo" : "-bar"
     r = uuid4()