From 3d544233a63a2105d8d91e7fd4f62f7703fef6e0 Mon Sep 17 00:00:00 2001
From: default <nobody@localhost>
Date: Fri, 30 Sep 2022 09:56:29 +0200
Subject: [PATCH] Timeline is cached.

---
 data.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 html.c | 21 +++++++++++++++++----
 snac.h |  5 +++++
 3 files changed, 77 insertions(+), 5 deletions(-)

diff --git a/data.c b/data.c
index ee21a98..5eb729c 100644
--- a/data.c
+++ b/data.c
@@ -178,7 +178,7 @@ float mtime(char *fn)
     struct stat st;
     float r = 0.0;
 
-    if (stat(fn, &st) != -1)
+    if (fn && stat(fn, &st) != -1)
         r = (float)st.st_mtim.tv_sec;
 
     return r;
@@ -275,6 +275,13 @@ d_char *follower_list(snac *snac)
 }
 
 
+float timeline_mtime(snac *snac)
+{
+    xs *fn = xs_fmt("%s/timeline", snac->basedir);
+    return mtime(fn);
+}
+
+
 d_char *_timeline_find_fn(snac *snac, char *id)
 /* returns the file name of a timeline entry by its id */
 {
@@ -831,6 +838,53 @@ int static_get(snac *snac, char *id, d_char **data, int *size)
 }
 
 
+d_char *_history_fn(snac *snac, char *id)
+/* gets the filename for the history */
+{
+    return xs_fmt("%s/history/%s", snac->basedir, id);
+}
+
+
+float history_mtime(snac *snac, char * id)
+{
+    float t = 0.0;
+    xs *fn = _history_fn(snac, id);
+
+    if (fn != NULL)
+        t = mtime(fn);
+
+    return t;
+}
+
+
+void history_add(snac *snac, char *id, char *content, int size)
+/* adds something to the history */
+{
+    xs *fn = _history_fn(snac, id);
+    FILE *f;
+
+    if ((f = fopen(fn, "w")) != NULL) {
+        fwrite(content, size, 1, f);
+        fclose(f);
+    }
+}
+
+
+d_char *history_get(snac *snac, char *id)
+{
+    d_char *content = NULL;
+    xs *fn = _history_fn(snac, id);
+    FILE *f;
+
+    if ((f = fopen(fn, "r")) != NULL) {
+        content = xs_readall(f);
+        fclose(f);
+    }
+
+    return content;
+}
+
+
 void enqueue_input(snac *snac, char *msg, char *req, int retries)
 /* enqueues an input message */
 {
diff --git a/html.c b/html.c
index fc42fb3..fd6fbdf 100644
--- a/html.c
+++ b/html.c
@@ -713,11 +713,24 @@ int html_get_handler(d_char *req, char *q_path, char **body, int *b_size, char *
         if (!login(&snac, req))
             status = 401;
         else {
-            xs *list = timeline_list(&snac, 0xfffffff);
+            if (history_mtime(&snac, "_timeline.html") > timeline_mtime(&snac)) {
+                snac_debug(&snac, 1, xs_fmt("serving cached timeline"));
 
-            *body   = html_timeline(&snac, list, 0);
-            *b_size = strlen(*body);
-            status  = 200;
+                *body   = history_get(&snac, "_timeline.html");
+                *b_size = strlen(*body);
+                status  = 200;
+            }
+            else {
+                snac_debug(&snac, 1, xs_fmt("building timeline"));
+
+                xs *list = timeline_list(&snac, 0xfffffff);
+
+                *body   = html_timeline(&snac, list, 0);
+                *b_size = strlen(*body);
+                status  = 200;
+
+                history_add(&snac, "_timeline.html", *body, *b_size);
+            }
         }
     }
     else
diff --git a/snac.h b/snac.h
index 392f57d..451fd78 100644
--- a/snac.h
+++ b/snac.h
@@ -60,6 +60,7 @@ int follower_del(snac *snac, char *actor);
 int follower_check(snac *snac, char *actor);
 d_char *follower_list(snac *snac);
 
+float timeline_mtime(snac *snac);
 int timeline_here(snac *snac, char *id);
 d_char *_timeline_find_fn(snac *snac, char *id);
 d_char *timeline_find(snac *snac, char *id);
@@ -84,6 +85,10 @@ int actor_get(snac *snac, char *actor, d_char **data);
 
 int static_get(snac *snac, char *id, d_char **data, int *size);
 
+float history_mtime(snac *snac, char *id);
+void history_add(snac *snac, char *id, char *content, int size);
+d_char *history_get(snac *snac, char *id);
+
 void enqueue_input(snac *snac, char *msg, char *req, int retries);
 void enqueue_output(snac *snac, char *msg, char *actor, int retries);