# HG changeset patch
# User paulo
# Date 1643899184 28800
# Node ID 41a6e2d99f683fa0e25f376c05df73fa51fc7972
# Parent  99e4022eae522c2929c94f8fd34fa4e328c00f8a
pics3: add blob cache

diff -r 99e4022eae52 -r 41a6e2d99f68 pics3/pics_flask_app.py
--- a/pics3/pics_flask_app.py	Thu Jan 20 01:28:46 2022 -0800
+++ b/pics3/pics_flask_app.py	Thu Feb 03 06:39:44 2022 -0800
@@ -2,6 +2,7 @@
 import datetime
 import random
 import os
+import time
 
 import flask
 import google.cloud.storage
@@ -31,6 +32,29 @@
 PICSDIALECT = PicsDialect()
 
 
+class BlobCache(object):
+  def __init__(self):
+    self._bloblist_cache = {}
+    self._bloblist_ttl = 60*15  # 15 minutes
+    self._public_url_cache = {}
+
+  def get_list_blobs(self, prefix):
+    if (prefix not in self._bloblist_cache
+        or time.time() > (self._bloblist_cache[prefix][1] + self._bloblist_ttl)):
+      self._bloblist_cache[prefix] = ([i for i in GCS_CLIENT.list_blobs(GCS_BUCKET, prefix=prefix)],
+                                      time.time())
+    return self._bloblist_cache[prefix][0]
+
+  def cache_public_url(self, blob):
+    if blob.name not in self._public_url_cache:
+      self._public_url_cache[blob.name] = blob.public_url
+
+  def get_public_url(self, blob_name):
+    return self._public_url_cache[blob_name]
+
+BLOBCACHE = BlobCache()
+
+
 def _parse_dt(dts):
   return datetime.datetime.strptime(dts, "%Y%m%d")
 
@@ -48,10 +72,18 @@
   thumb_dir = f"pics/{d}/thumbs"
   browse_dir = f"pics/{d}/browse"
 
-  thumb_fns = [i.name for i in GCS_CLIENT.list_blobs(GCS_BUCKET, prefix=thumb_dir) if i.name.endswith(exts)]
+  thumb_fns = []
+  for i in BLOBCACHE.get_list_blobs(thumb_dir):
+    if i.name.endswith(exts):
+      thumb_fns.append(i.name)
+      BLOBCACHE.cache_public_url(i)
   thumb_fns = sorted(thumb_fns, key=_numeric_pad_basename)
 
-  browse_contents = set(i.name for i in GCS_CLIENT.list_blobs(GCS_BUCKET, prefix=browse_dir) if i.name.endswith(exts))
+  browse_contents = set()
+  for i in BLOBCACHE.get_list_blobs(browse_dir):
+    if i.name.endswith(exts):
+      browse_contents.add(i.name)
+      BLOBCACHE.cache_public_url(i)
   browse_fns = []
   for i in thumb_fns:
     i_basename = os.path.splitext(os.path.basename(i))[0]
@@ -83,7 +115,7 @@
   
 
 def _go_thumbnail_links_to_browse_imgs_html_body(body, d, t, b, a_args={}, img_args={}, lazyload=False):
-  thumb_img_url = GCS_BUCKET.get_blob(t).public_url
+  thumb_img_url = BLOBCACHE.get_public_url(t)
   browse_url = flask.url_for("browse", d=d, img=os.path.basename(b))
   
   a = body.a(href=browse_url, **a_args)
@@ -98,7 +130,7 @@
 
 
 def _go_thumbnail_links_to_thumbs_html_body(body, d, t, a_args={}, img_args={}):
-  thumb_img_url = GCS_BUCKET.get_blob(t).public_url
+  thumb_img_url = BLOBCACHE.get_public_url(t)
   thumbs_url_args = {"from": os.path.basename(t), "_anchor": "selected"}
   thumbs_url = flask.url_for("thumbs", d=d, **thumbs_url_args)
   
@@ -208,7 +240,6 @@
 @app.route("/<d>")
 def thumbs(d):
   args = flask.request.args
-  print(f"args = {args}")
 
   from_img = args.get("from")