Implement makeTempDirSync()

9 files changed, 188 insertions, 25 deletions

diff --git a/BUILD.gn b/BUILD.gn
index c5f28dcbe..2e487738f 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -43,6 +43,7 @@ main_extern = [
   "$rust_build:log",
   "$rust_build:sha1",
   "$rust_build:tempfile",
+  "$rust_build:rand",
   "$rust_build:tokio",
   "$rust_build:tokio_current_thread",
   "$rust_build:url",
diff --git a/Cargo.toml b/Cargo.toml
index 7d73ede4c..c6ebbbf15 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,6 +11,7 @@ version = "0.0.0"
 url = "1.7.1"
 libc = "0.2.42"
 log = "0.4.3"
+rand = "0.5.4"
 sha1 = "0.6.0"
 tempfile = "3"
 tokio = {git = "https://github.com/tokio-rs/tokio.git", rev = "5d0d2a2e1214f856993df6965825c89bfcaa879e"}
diff --git a/js/deno.ts b/js/deno.ts
index 63bee0b7c..7a5c4217e 100644
--- a/js/deno.ts
+++ b/js/deno.ts
@@ -1,5 +1,5 @@
 // Copyright 2018 the Deno authors. All rights reserved. MIT license.
 // Public deno module.
-export { exit, readFileSync, writeFileSync } from "./os";
+export { exit, makeTempDirSync, readFileSync, writeFileSync } from "./os";
 export { libdeno } from "./libdeno";
 export const argv: string[] = [];
diff --git a/js/os.ts b/js/os.ts
index 3104c5013..10ba32f9d 100644
--- a/js/os.ts
+++ b/js/os.ts
@@ -85,6 +85,57 @@ export function codeCache(
   }
 }
 
+/**
+ * makeTempDirSync creates a new temporary directory in the directory `dir`, its
+ * name beginning with `prefix` and ending with `suffix`.
+ * It returns the full path to the newly created directory.
+ * If `dir` is unspecified, tempDir uses the default directory for temporary
+ * files. Multiple programs calling tempDir simultaneously will not choose the
+ * same directory. It is the caller's responsibility to remove the directory
+ * when no longer needed.
+ */
+export interface MakeTempDirOptions {
+  dir?: string;
+  prefix?: string;
+  suffix?: string;
+}
+export function makeTempDirSync({
+  dir,
+  prefix,
+  suffix
+}: MakeTempDirOptions = {}): string {
+  const builder = new flatbuffers.Builder();
+  const fbDir = dir == null ? -1 : builder.createString(dir);
+  const fbPrefix = prefix == null ? -1 : builder.createString(prefix);
+  const fbSuffix = suffix == null ? -1 : builder.createString(suffix);
+  fbs.MakeTempDir.startMakeTempDir(builder);
+  if (dir != null) {
+    fbs.MakeTempDir.addDir(builder, fbDir);
+  }
+  if (prefix != null) {
+    fbs.MakeTempDir.addPrefix(builder, fbPrefix);
+  }
+  if (suffix != null) {
+    fbs.MakeTempDir.addSuffix(builder, fbSuffix);
+  }
+  const msg = fbs.MakeTempDir.endMakeTempDir(builder);
+  fbs.Base.startBase(builder);
+  fbs.Base.addMsg(builder, msg);
+  fbs.Base.addMsgType(builder, fbs.Any.MakeTempDir);
+  builder.finish(fbs.Base.endBase(builder));
+  const resBuf = libdeno.send(builder.asUint8Array());
+  assert(resBuf != null);
+  const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf!));
+  const baseRes = fbs.Base.getRootAsBase(bb);
+  maybeThrowError(baseRes);
+  assert(fbs.Any.MakeTempDirRes === baseRes.msgType());
+  const res = new fbs.MakeTempDirRes();
+  assert(baseRes.msg(res) != null);
+  const path = res.path();
+  assert(path != null);
+  return path!;
+}
+
 export function readFileSync(filename: string): Uint8Array {
   /* Ideally we could write
   const res = send({
diff --git a/js/unit_tests.ts b/js/unit_tests.ts
index 17ddd5256..92957c493 100644
--- a/js/unit_tests.ts
+++ b/js/unit_tests.ts
@@ -41,16 +41,16 @@ test(function tests_readFileSync_NotFound() {
 });
 */
 
-/* TODO(ry) Add this once we can create a tmpDir to write the file into.
-test(function writeFileSyncSuccess() {
+testPerm({ write: true }, function writeFileSync() {
   const enc = new TextEncoder();
-  const dataWritten = enc.encode("Hello");
-  const filename = "TEMPDIR/test.txt";
-  deno.writeFileSync(filename, dataWritten, 0o666);
+  const data = enc.encode("Hello");
+  const filename = deno.makeTempDirSync() + "/test.txt";
+  deno.writeFileSync(filename, data, 0o666);
   const dataRead = deno.readFileSync(filename);
-  assertEqual(dataRead, dataWritten);
+  const dec = new TextDecoder("utf-8");
+  const actual = dec.decode(dataRead);
+  assertEqual("Hello", actual);
 });
-*/
 
 // For this test to pass we need --allow-write permission.
 // Otherwise it will fail with deno.PermissionDenied instead of deno.NotFound.
@@ -70,23 +70,48 @@ testPerm({ write: true }, function writeFileSyncFail() {
   assert(caughtError);
 });
 
+testPerm({ write: true }, function makeTempDirSync() {
+  const dir1 = deno.makeTempDirSync({ prefix: "hello", suffix: "world" });
+  const dir2 = deno.makeTempDirSync({ prefix: "hello", suffix: "world" });
+  // Check that both dirs are different.
+  assert(dir1 != dir2);
+  for (const dir of [dir1, dir2]) {
+    // Check that the prefix and suffix are applied.
+    const lastPart = dir.replace(/^.*[\\\/]/, "");
+    assert(lastPart.startsWith("hello"));
+    assert(lastPart.endsWith("world"));
+  }
+  // Check that the `dir` option works.
+  const dir3 = deno.makeTempDirSync({ dir: dir1 });
+  assert(dir3.startsWith(dir1));
+  assert(/^[\\\/]/.test(dir3.slice(dir1.length)));
+  // Check that creating a temp dir inside a nonexisting directory fails.
+  let err;
+  try {
+    deno.makeTempDirSync({ dir: "/baddir" });
+  } catch (err_) {
+    err = err_;
+  }
+  // TODO assert(err instanceof deno.NotFound).
+  assert(err);
+  assertEqual(err.name, "deno.NotFound");
+});
+
+test(function makeTempDirSyncPerm() {
+  // makeTempDirSync should require write permissions (for now).
+  let err;
+  try {
+    deno.makeTempDirSync({ dir: "/baddir" });
+  } catch (err_) {
+    err = err_;
+  }
+  // TODO assert(err instanceof deno.PermissionDenied).
+  assert(err);
+  assertEqual(err.name, "deno.PermissionDenied");
+});
+
 testPerm({ net: true }, async function tests_fetch() {
   const response = await fetch("http://localhost:4545/package.json");
   const json = await response.json();
   assertEqual(json.name, "deno");
 });
-
-/*
-test(async function tests_writeFileSync() {
-  const enc = new TextEncoder();
-  const data = enc.encode("Hello");
-  // TODO need ability to get tmp dir.
-  const fn = "/tmp/test.txt";
-  writeFileSync("/tmp/test.txt", data, 0o666);
-  const dataRead = deno.readFileSync("/tmp/test.txt");
-  const dec = new TextDecoder("utf-8");
-  const actual = dec.decode(dataRead);
-  assertEqual("Hello", actual);
-});
-
-*/
diff --git a/src/fs.rs b/src/fs.rs
index 50c99c593..786c35691 100644
--- a/src/fs.rs
+++ b/src/fs.rs
@@ -1,13 +1,41 @@
 use std;
-use std::fs::File;
+use std::fs::{create_dir, File};
+use std::io::ErrorKind;
 use std::io::Write;
-use std::path::Path;
+use std::path::{Path, PathBuf};
+
+use rand;
+use rand::RngCore;
 
 pub fn write_file_sync(path: &Path, content: &[u8]) -> std::io::Result<()> {
   let mut f = File::create(path)?;
   f.write_all(content)
 }
 
+pub fn make_temp_dir(
+  dir: Option<&Path>,
+  prefix: Option<&str>,
+  suffix: Option<&str>,
+) -> std::io::Result<PathBuf> {
+  let prefix_ = prefix.unwrap_or("");
+  let suffix_ = suffix.unwrap_or("");
+  let mut buf: PathBuf = match dir {
+    Some(ref p) => p.to_path_buf(),
+    None => std::env::temp_dir(),
+  }.join("_");
+  loop {
+    let unique = rand::thread_rng().next_u32();
+    buf.set_file_name(format!("{}{:08x}{}", prefix_, unique, suffix_));
+    // TODO: on posix, set mode flags to 0o700.
+    let r = create_dir(buf.as_path());
+    match r {
+      Err(ref e) if e.kind() == ErrorKind::AlreadyExists => continue,
+      Ok(_) => return Ok(buf),
+      Err(e) => return Err(e),
+    }
+  }
+}
+
 pub fn mkdir(path: &Path) -> std::io::Result<()> {
   debug!("mkdir -p {}", path.display());
   assert!(path.has_root(), "non-has_root not yet implemented");
diff --git a/src/handlers.rs b/src/handlers.rs
index 4638288ca..866ca8b3a 100644
--- a/src/handlers.rs
+++ b/src/handlers.rs
@@ -65,6 +65,13 @@ pub extern "C" fn msg_from_js(d: *const DenoC, buf: deno_buf) {
       let msg = msg::Exit::init_from_table(base.msg().unwrap());
       std::process::exit(msg.code())
     }
+    msg::Any::MakeTempDir => {
+      let msg = msg::MakeTempDir::init_from_table(base.msg().unwrap());
+      let dir = msg.dir();
+      let prefix = msg.prefix();
+      let suffix = msg.suffix();
+      handle_make_temp_dir(d, &mut builder, dir, prefix, suffix)
+    }
     msg::Any::ReadFileSync => {
       // TODO base.msg_as_ReadFileSync();
       let msg = msg::ReadFileSync::init_from_table(base.msg().unwrap());
@@ -395,6 +402,43 @@ fn send_timer_ready(d: *const DenoC, timer_id: u32, done: bool) {
   );
 }
 
+fn handle_make_temp_dir(
+  d: *const DenoC,
+  builder: &mut FlatBufferBuilder,
+  dir: Option<&str>,
+  prefix: Option<&str>,
+  suffix: Option<&str>,
+) -> HandlerResult {
+  let deno = from_c(d);
+  if !deno.flags.allow_write {
+    let err = std::io::Error::new(
+      std::io::ErrorKind::PermissionDenied,
+      "allow_write is off.",
+    );
+    return Err(err.into());
+  }
+  // TODO(piscisaureus): use byte vector for paths, not a string.
+  // See https://github.com/denoland/deno/issues/627.
+  // We can't assume that paths are always valid utf8 strings.
+  let path = deno_fs::make_temp_dir(dir.map(Path::new), prefix, suffix)?;
+  let path_off = builder.create_string(path.to_str().unwrap());
+  let msg = msg::MakeTempDirRes::create(
+    builder,
+    &msg::MakeTempDirResArgs {
+      path: Some(path_off),
+      ..Default::default()
+    },
+  );
+  Ok(create_msg(
+    builder,
+    &msg::BaseArgs {
+      msg: Some(flatbuffers::Offset::new(msg.value())),
+      msg_type: msg::Any::MakeTempDirRes,
+      ..Default::default()
+    },
+  ))
+}
+
 // Prototype https://github.com/denoland/deno/blob/golang/os.go#L171-L184
 fn handle_read_file_sync(
   _d: *const DenoC,
diff --git a/src/main.rs b/src/main.rs
index 28e852fdc..6a013bea0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ extern crate futures;
 extern crate hyper;
 extern crate libc;
 extern crate msg_rs as msg_generated;
+extern crate rand;
 extern crate sha1;
 extern crate tempfile;
 extern crate tokio;
diff --git a/src/msg.fbs b/src/msg.fbs
index a20af6892..162a8ddee 100644
--- a/src/msg.fbs
+++ b/src/msg.fbs
@@ -12,6 +12,8 @@ union Any {
   TimerClear,
   FetchReq,
   FetchRes,
+  MakeTempDir,
+  MakeTempDirRes,
   ReadFileSync,
   ReadFileSyncRes,
   WriteFileSync,
@@ -133,6 +135,16 @@ table FetchRes {
   body: [ubyte];
 }
 
+table MakeTempDir {
+  dir: string;
+  prefix: string;
+  suffix: string;
+}
+
+table MakeTempDirRes {
+  path: string;
+}
+
 table ReadFileSync {
   filename: string;
 }