From 42a0f5be0055199ba9ca4627444ee192ab0c48a8 Mon Sep 17 00:00:00 2001
From: Bojan Serafimov <bojan.serafimov7@gmail.com>
Date: Thu, 6 Oct 2022 13:18:31 -0400
Subject: [PATCH] WIP

---
 control_plane/src/storage.rs             |  7 +++---
 pageserver/src/lib.rs                    |  2 +-
 pgxn/neon/libpagestore.c                 | 28 ++++++++++++++----------
 test_runner/fixtures/compare_fixtures.py |  4 ++--
 4 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/control_plane/src/storage.rs b/control_plane/src/storage.rs
index 933b7b7b65..7af3170799 100644
--- a/control_plane/src/storage.rs
+++ b/control_plane/src/storage.rs
@@ -61,7 +61,7 @@ impl ResponseErrorMessageExt for Response {
         let url = self.url().to_owned();
         Err(PageserverHttpError::Response(
             match self.json::<HttpErrorBody>() {
-                Ok(err_body) => format!("Error: {}", err_body.msg),
+                Ok(err_body) => format!("Response error: {}", err_body.msg),
                 Err(_) => format!("Http error ({}) at {}.", status.as_u16(), url),
             },
         ))
@@ -181,14 +181,15 @@ impl PageServerNode {
         new_timeline_id: Option<TimelineId>,
         pg_version: u32,
     ) -> anyhow::Result<TimelineId> {
-        let initial_tenant_id = self.tenant_create(new_tenant_id, HashMap::new())?;
+        let initial_tenant_id = self.tenant_create(new_tenant_id, HashMap::new())
+            .context("Failed to create tenant")?;
         let initial_timeline_info = self.timeline_create(
             initial_tenant_id,
             new_timeline_id,
             None,
             None,
             Some(pg_version),
-        )?;
+        ).context("Failed to create timeline")?;
         Ok(initial_timeline_info.timeline_id)
     }
 
diff --git a/pageserver/src/lib.rs b/pageserver/src/lib.rs
index 9f31907a0b..6f935be709 100644
--- a/pageserver/src/lib.rs
+++ b/pageserver/src/lib.rs
@@ -16,7 +16,7 @@ pub mod tenant;
 pub mod tenant_config;
 pub mod tenant_mgr;
 pub mod tenant_tasks;
-pub mod timelines;
+// pub mod timelines;
 pub mod trace;
 pub mod virtual_file;
 pub mod walingest;
diff --git a/pgxn/neon/libpagestore.c b/pgxn/neon/libpagestore.c
index 6b6a042402..452fd871a3 100644
--- a/pgxn/neon/libpagestore.c
+++ b/pgxn/neon/libpagestore.c
@@ -272,7 +272,8 @@ typedef struct
 
 	// Points directly to a NeonResponse. We can't just own the
 	// NeonResponse because it's a "supertype", so it's not Sized.
-	StringInfo response;
+	char* response;
+	int len;
 }            NeonRequestResponse;
 
 NeonRequestResponse page_cache[20];
@@ -285,13 +286,16 @@ pageserver_call(NeonRequest * request)
 	// Compute hash
 	char hash = 0;
 	StringInfoData req_buff;
-	req_buff = zm_pack_request(request);
+	req_buff = nm_pack_request(request);
 	for (int i = 0; i < req_buff.len; i++) {
 		hash ^= req_buff.data[i];
 	}
 	pfree(req_buff.data);
 
 	// If result is cached, memcpy and return
+	// HACK keeping this commented out until I see why updating the
+	//      cache causes segfault.
+	//
 	// for (int i = 0; i < page_cache_size; i++) {
 	// 	if (page_cache[i].request_hash == hash) {
 	// 		int len = page_cache[0].response->len;
@@ -318,15 +322,17 @@ pageserver_call(NeonRequest * request)
 	}
 
 	// Cache result
-	// page_cache[page_cache_head].request_hash = hash;
-	// page_cache[page_cache_head].response->len = len;
-	// // TODO free old result
-	// page_cache[page_cache_head].response->data = palloc0(len);
-	// memcpy(page_cache[page_cache_head].response->data, resp, len);
-	// page_cache_head = (page_cache_head + 1) % 20;
-	// if (page_cache_size < 20) {
-	// 	page_cache_size += 1;
-	// }
+	page_cache[page_cache_head].request_hash = hash;
+	if (page_cache_head < page_cache_size) {
+		pfree(page_cache[page_cache_head].response);
+	}
+	page_cache[page_cache_head].len = len;
+	page_cache[page_cache_head].response = palloc(len);
+	memcpy(page_cache[page_cache_head].response, resp, len);
+	page_cache_head = (page_cache_head + 1) % 20;
+	if (page_cache_size < 20) {
+		page_cache_size += 1;
+	}
 
 	return resp;
 }
diff --git a/test_runner/fixtures/compare_fixtures.py b/test_runner/fixtures/compare_fixtures.py
index c5be558cd4..af71491df8 100644
--- a/test_runner/fixtures/compare_fixtures.py
+++ b/test_runner/fixtures/compare_fixtures.py
@@ -124,10 +124,10 @@ class NeonCompare(PgCompare):
         return self._pg_bin
 
     def flush(self):
-        self.pageserver_http_client.timeline_gc(self.env.initial_tenant, self.timeline, 0)
+        self.pageserver_http_client.timeline_gc(self.tenant, self.timeline, 0)
 
     def compact(self):
-        self.pageserver_http_client.timeline_compact(self.env.initial_tenant, self.timeline)
+        self.pageserver_http_client.timeline_compact(self.tenant, self.timeline)
 
     def report_peak_memory_use(self) -> None:
         self.zenbenchmark.record(