From aa7b32d892f913439fb9b3e8fa4394d0eceaa8ae Mon Sep 17 00:00:00 2001
From: Bojan Serafimov <bojan.serafimov7@gmail.com>
Date: Wed, 16 Mar 2022 18:42:58 -0400
Subject: [PATCH] Simplify

---
 pageserver/src/bin/psbench.rs | 88 ++++++++++++++++++++++++-----------
 1 file changed, 61 insertions(+), 27 deletions(-)

diff --git a/pageserver/src/bin/psbench.rs b/pageserver/src/bin/psbench.rs
index 6a5124e41b..f9161ff2cd 100644
--- a/pageserver/src/bin/psbench.rs
+++ b/pageserver/src/bin/psbench.rs
@@ -2,9 +2,10 @@
 //!
 //! Usually it's easier to write python perf tests, but here the performance
 //! of the tester matters, and the API is easier to work with from rust.
-use std::{io::{BufRead, BufReader, Cursor}, net::SocketAddr};
+use std::{collections::HashMap, io::{BufRead, BufReader, Cursor}, net::SocketAddr};
+use byteorder::ReadBytesExt;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
-use bytes::{Bytes, BytesMut};
+use bytes::{BufMut, Bytes, BytesMut};
 use clap::{App, Arg};
 use std::fs::File;
 use zenith_utils::{GIT_VERSION, pq_proto::{BeMessage, BeParameterStatusMessage, FeMessage}};
@@ -19,21 +20,16 @@ pub fn read_lines_buffered(file_name: &str) -> impl Iterator<Item = String> {
 
 pub async fn get_page(
     pagestream: &mut tokio::net::TcpStream,
-    lsn: &Vec<u8>,
-    page: &Vec<u8>,
+    lsn: &Lsn,
+    page: &Page,
 ) -> anyhow::Result<Vec<u8>> {
     let msg = {
         let query = {
-            use bytes::buf::BufMut;
             let mut query = BytesMut::new();
             query.put_u8(2);  // Specifies get_page query
             query.put_u8(0);  // Specifies this is not a "latest page" query
-            for byte in lsn {
-                query.put_u8(*byte);
-            }
-            for byte in page {
-                query.put_u8(*byte);
-            }
+            query.put_u64(lsn.0);
+            page.write(&mut query);
             query.freeze()
         };
 
@@ -52,7 +48,7 @@ pub async fn get_page(
 
     let page = {
         let mut cursor = Cursor::new(response);
-        let tag = cursor.read_u8().await?;
+        let tag = AsyncReadExt::read_u8(&mut cursor).await?;
         if tag != 102 {
             panic!("AA");
         }
@@ -70,6 +66,41 @@ pub async fn get_page(
     Ok(page)
 }
 
+#[derive(Copy, Clone)]
+pub struct Lsn(pub u64);
+
+#[derive(Copy, Clone)]
+pub struct Page {
+    spcnode: u32,
+    dbnode: u32,
+    relnode: u32,
+    forknum: u8,
+    blkno: u32,
+}
+
+impl Page {
+    async fn read<Reader>(buf: &mut Reader) -> Result<Page>
+    where
+        Reader: tokio::io::AsyncRead + Unpin,
+    {
+        let spcnode = buf.read_u32().await?;
+        let dbnode = buf.read_u32().await?;
+        let relnode = buf.read_u32().await?;
+        let forknum = buf.read_u8().await?;
+        let blkno = buf.read_u32().await?;
+        Ok(Page { spcnode, dbnode, relnode, forknum, blkno })
+    }
+
+    async fn write(&self, buf: &mut BytesMut) -> Result<()> {
+        buf.put_u32(self.spcnode);
+        buf.put_u32(self.dbnode);
+        buf.put_u32(self.relnode);
+        buf.put_u8(self.forknum);
+        buf.put_u32(self.blkno);
+        Ok(())
+    }
+}
+
 #[tokio::main]
 async fn main() -> Result<()> {
 
@@ -109,21 +140,19 @@ async fn main() -> Result<()> {
     let tenant_hex = arg_matches.value_of("tenant_hex").unwrap();
     let timeline = arg_matches.value_of("timeline").unwrap();
 
-    let lsn_page_pairs: Vec<_> = read_lines_buffered(log_file)
-        .filter_map(|line| line.strip_prefix("wal-at-lsn-modified-page ").map(|x| x.to_string()))
-        .map(|rest| {
-            let (lsn, page) = rest.split_once(" ").unwrap();
-            let lsn = hex::decode(lsn).unwrap();
-            if lsn.len() != 8 {
-                panic!("AAA")
-            }
-            let page = hex::decode(page).unwrap();
-            if page.len() != 17 {
-                panic!("AAA")
-            }
-            (lsn, page)
-        })
-        .collect();
+    let relevant = read_lines_buffered(log_file) .filter_map(|line| line.strip_prefix("wal-at-lsn-modified-page ").map(|x| x.to_string()));
+    let mut lsn_page_pairs = Vec::<(Lsn, Page)>::new();
+    for line in relevant {
+        let (lsn, page) = line.split_once(" ").unwrap();
+
+        let lsn = hex::decode(lsn)?;
+        let lsn = Lsn(AsyncReadExt::read_u64(&mut Cursor::new(lsn)).await?);
+
+        let page = hex::decode(page)?;
+        let page = Page::read(&mut Cursor::new(page)).await?;
+
+        lsn_page_pairs.push((lsn, page))
+    }
 
     // Get raw TCP connection to the pageserver postgres protocol port
     let mut socket = tokio::net::TcpStream::connect("localhost:15000").await?;
@@ -145,5 +174,10 @@ async fn main() -> Result<()> {
     let (some_lsn, some_page) = lsn_page_pairs[0].clone();
     let _page = get_page(&mut socket, &some_lsn, &some_page).await?;
 
+    // TODO
+    // 1. print writes per page
+    // 2. Generate high writes per page
+    // 3. Test runtime
+
     Ok(())
 }