From db733af9a4531f56305956b5d2dec87d93ab8125 Mon Sep 17 00:00:00 2001
From: Matthijs Piek <2212627+MatthijsPiek@users.noreply.github.com>
Date: Thu, 9 Nov 2023 11:04:20 +0100
Subject: [PATCH] Reduce the amount of ListRequests for a recursive put for
 targets not ending in "/"

---
 s3fs/core.py            | 44 ++++++++++++++++++++---------------------
 s3fs/tests/test_s3fs.py | 37 ++++++++++++++++++++++++++++------
 2 files changed, 53 insertions(+), 28 deletions(-)

diff --git a/s3fs/core.py b/s3fs/core.py
index 5d0247f4..d2d7d159 100644
--- a/s3fs/core.py
+++ b/s3fs/core.py
@@ -718,7 +718,7 @@ async def _lsdir(
             except ClientError as e:
                 raise translate_boto_error(e)
 
-            if delimiter and files and not versions:
+            if delimiter and not versions:
                 self.dircache[path] = files
             return files
         return self.dircache[path]
@@ -1001,13 +1001,18 @@ async def _ls(self, path, detail=False, refresh=False, versions=False):
     def _exists_in_cache(self, path, bucket, key, version_id):
         fullpath = "/".join((bucket, key))
 
+        entries = None
         try:
             entries = self._ls_from_cache(fullpath)
         except FileNotFoundError:
-            return False
+            pass
 
         if entries is None:
-            return None
+            children = [key for key in self.dircache.keys() if key.startswith(fullpath)]
+            if len(children) == 0:
+                return None
+            else:
+                return True  # if children exist, the parent also exists
 
         if not self.version_aware or version_id is None:
             return True
@@ -1036,27 +1041,22 @@ async def _exists(self, path):
                 return True
             except FileNotFoundError:
                 return False
-        elif self.dircache.get(bucket, False):
-            return True
         else:
-            try:
-                if self._ls_from_cache(bucket):
-                    return True
-            except FileNotFoundError:
-                # might still be a bucket we can access but don't own
-                pass
-            try:
-                await self._call_s3(
-                    "list_objects_v2", MaxKeys=1, Bucket=bucket, **self.req_kw
-                )
-                return True
-            except Exception:
-                pass
-            try:
-                await self._call_s3("get_bucket_location", Bucket=bucket, **self.req_kw)
+            if self._exists_in_cache(path, bucket, key, version_id):
                 return True
-            except Exception:
-                return False
+            else:
+                try:
+                    await self._call_s3(
+                        "list_objects_v2", MaxKeys=1, Bucket=bucket, **self.req_kw
+                    )
+                    return True
+                except Exception:
+                    pass
+                try:
+                    await self._call_s3("get_bucket_location", Bucket=bucket, **self.req_kw)
+                    return True
+                except Exception:
+                    return False
 
     exists = sync_wrapper(_exists)
 
diff --git a/s3fs/tests/test_s3fs.py b/s3fs/tests/test_s3fs.py
index b243ff1f..af248431 100644
--- a/s3fs/tests/test_s3fs.py
+++ b/s3fs/tests/test_s3fs.py
@@ -2613,11 +2613,12 @@ def test_get_directory_recursive(s3, tmpdir):
         assert target_fs.find(target) == [os.path.join(target, "file")]
 
 
-def test_put_directory_recursive(s3, tmpdir):
+def test_put_directory_recursive(s3, tmpdir, request_count):
     src = os.path.join(tmpdir, "src")
-    src_file = os.path.join(src, "file")
+    deep_src_path = os.path.join(src, "very", "deep")
+    src_file = os.path.join(deep_src_path, "file")
     source_fs = fsspec.filesystem("file")
-    source_fs.mkdir(src)
+    source_fs.mkdir(deep_src_path)
     source_fs.touch(src_file)
 
     target = test_bucket_name + "/target"
@@ -2629,18 +2630,42 @@ def test_put_directory_recursive(s3, tmpdir):
         assert s3.isdir(target)
 
         if loop == 0:
-            assert s3.find(target) == [target + "/file"]
+            assert s3.find(target) == [target + "/very/deep/file"]
         else:
-            assert sorted(s3.find(target)) == [target + "/file", target + "/src/file"]
+            assert sorted(s3.find(target)) == [target + "/src/very/deep/file", target + "/very/deep/file"]
 
     s3.rm(target, recursive=True)
 
     # put with slash
     assert not s3.exists(target)
+
+
     for loop in range(2):
+        s3.dircache.clear()
+        request_count.clear()
+
         s3.put(src + "/", target, recursive=True)
+
+        assert request_count.get("PutObject", 0) == 1
+        assert request_count.get("ListObjectsV2", 0) <= 1
+
         assert s3.isdir(target)
-        assert s3.find(target) == [target + "/file"]
+        assert s3.find(target) == [target + "/very/deep/file"]
+
+
+@pytest.fixture()
+def request_count(s3):
+    count = {}
+
+    def count_requests(request, operation_name, **kwargs):
+        nonlocal count
+        count[operation_name] = count.get(operation_name, 0) + 1
+
+    s3.s3.meta.events.register("request-created.s3", count_requests)
+
+    yield count
+
+    s3.s3.meta.events.unregister("request-created.s3", count_requests)
 
 
 def test_cp_two_files(s3):