From 1e981e69a6cf55ebe095f1584da20bae6a259d0c Mon Sep 17 00:00:00 2001
From: Determinant <tederminant@gmail.com>
Date: Tue, 9 Jun 2020 23:46:55 -0400
Subject: ...

---
 examples/demo1.rs | 77 +++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 67 insertions(+), 10 deletions(-)

(limited to 'examples')

diff --git a/examples/demo1.rs b/examples/demo1.rs
index 0f50ec3..536aba2 100644
--- a/examples/demo1.rs
+++ b/examples/demo1.rs
@@ -1,27 +1,84 @@
 use growthring::{WALFile, WALStore, WALPos, WALBytes, WALLoader, WALWriter};
 
-struct WALFileFake {
-    filename: String
+use std::os::unix::io::RawFd;
+use nix::Error::Sys;
+use nix::errno::Errno;
+use nix::unistd::{close, mkdir, sysconf, SysconfVar};
+use nix::fcntl::{open, openat, OFlag, fallocate, FallocateFlags};
+use nix::sys::{stat::Mode, uio::pwrite};
+use libc::off_t;
+
+struct WALFileTest {
+    filename: String,
+    fd: RawFd,
+}
+
+impl WALFileTest {
+    fn new(rootfd: RawFd, filename: &str) -> Self {
+        let fd = openat(rootfd, filename,
+            OFlag::O_CREAT | OFlag::O_RDWR,
+            Mode::S_IRUSR | Mode::S_IWUSR).unwrap();
+        let filename = filename.to_string();
+        WALFileTest {
+            filename,
+            fd,
+        }
+    }
 }
 
-impl WALFile for WALFileFake {
+impl Drop for WALFileTest {
+    fn drop(&mut self) {
+        close(self.fd).unwrap();
+    }
+}
+
+impl WALFile for WALFileTest {
     fn allocate(&self, offset: WALPos, length: usize) {
         println!("{}.allocate(offset=0x{:x}, end=0x{:x})", self.filename, offset, offset + length as u64);
+        fallocate(self.fd, FallocateFlags::FALLOC_FL_ZERO_RANGE, offset as off_t, length as off_t);
     }
     fn write(&self, offset: WALPos, data: WALBytes) {
-        println!("{}.write(offset=0x{:x}, end=0x{:x}, data=0x{})", self.filename, offset, offset + data.len() as u64, hex::encode(data));
+        println!("{}.write(offset=0x{:x}, end=0x{:x}, data=0x{})",
+                self.filename, offset, offset + data.len() as u64, hex::encode(&data));
+        pwrite(self.fd, &*data, offset as off_t);
     }
     fn read(&self, offset: WALPos, length: usize) -> WALBytes {
-        Vec::new().into_boxed_slice()
+        unreachable!()
+    }
+}
+
+struct WALStoreTest {
+    rootfd: RawFd
+}
+
+impl WALStoreTest {
+    fn new(wal_dir: &str, truncate: bool) -> Self {
+        if truncate {
+            let _ = std::fs::remove_dir_all(wal_dir);
+        }
+        match mkdir(wal_dir, Mode::S_IRUSR | Mode::S_IWUSR | Mode::S_IXUSR) {
+            Err(e) => if truncate { panic!("error while creating directory: {}", e) },
+            Ok(_) => ()
+        }
+        let rootfd = match open(wal_dir, OFlag::O_DIRECTORY | OFlag::O_PATH, Mode::empty()) {
+            Ok(fd) => fd,
+            Err(_) => panic!("error while opening the DB")
+        };
+        WALStoreTest { rootfd }
+    }
+}
+
+impl Drop for WALStoreTest {
+    fn drop(&mut self) {
+        close(self.rootfd).unwrap();
     }
 }
 
-struct WALStoreFake;
-impl WALStore for WALStoreFake {
+impl WALStore for WALStoreTest {
     fn open_file(&self, filename: &str, touch: bool) -> Option<Box<dyn WALFile>> {
         println!("open_file(filename={}, touch={}", filename, touch);
         let filename = filename.to_string();
-        Some(Box::new(WALFileFake{ filename }))
+        Some(Box::new(WALFileTest::new(self.rootfd, &filename)))
     }
     fn remove_file(&self, filename: &str) -> bool {
         println!("remove_file(filename={})", filename);
@@ -36,7 +93,7 @@ impl WALStore for WALStoreFake {
     }
 }
 
-fn test(records: Vec<String>, wal: &mut WALWriter<WALStoreFake>) {
+fn test(records: Vec<String>, wal: &mut WALWriter<WALStoreTest>) {
     let records: Vec<WALBytes> = records.into_iter().map(|s| s.into_bytes().into_boxed_slice()).collect();
     let ret = wal.grow(&records);
     for ring_id in ret.iter() {
@@ -45,7 +102,7 @@ fn test(records: Vec<String>, wal: &mut WALWriter<WALStoreFake>) {
 }
 
 fn main() {
-    let store = WALStoreFake;
+    let store = WALStoreTest::new("./wal_demo1", true);
     let mut wal = WALLoader::new(store, 9, 8, 1000).recover();
     for _ in 0..3 {
         test(["hi", "hello", "lol"].iter().map(|s| s.to_string()).collect::<Vec<String>>(), &mut wal)
-- 
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