add wasm support

.travis.yml

@@ -13,7 +13,9 @@ env:
 sudo: false
 
 script:
+    - rustup target add wasm32-unknown-unknown
     - cargo build -v
+    - cargo check --target wasm32-unknown-unknown
     - cargo test -v --no-fail-fast
     - cargo test -v --no-fail-fast --features u2i
     - cd serde-tests && cargo test -v --no-fail-fast

Cargo.toml

@@ -29,11 +29,14 @@ serde = "1.0"
 serde_json = { version = "1.0", features = ["preserve_order"] }
 time = "0.1"
 linked-hash-map = "0.5"
-hostname = "0.1"
 hex = "0.3"
 md5 = "0.3"
 try_from = "0.2"
 
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+hostname = "0.1"
+libc = "0.2"
+
 [dev-dependencies]
 assert_matches = "1.2"
 serde_derive = "1.0"

src/lib.rs

@@ -45,8 +45,6 @@
 extern crate byteorder;
 extern crate chrono;
 extern crate hex;
-extern crate hostname;
-extern crate libc;
 extern crate linked_hash_map;
 extern crate rand;
 extern crate serde;
@@ -56,6 +54,11 @@ extern crate md5;
 extern crate time;
 extern crate try_from;
 
+#[cfg(not(target_arch = "wasm32"))]
+extern crate hostname;
+#[cfg(not(target_arch = "wasm32"))]
+extern crate libc;
+
 pub use self::bson::{Array, Bson, Document, TimeStamp, UtcDateTime};
 pub use self::decoder::{decode_document, decode_document_utf8_lossy, from_bson, Decoder, DecoderError, DecoderResult};
 pub use self::encoder::{encode_document, to_bson, Encoder, EncoderError, EncoderResult};

src/oid.rs

@@ -1,18 +1,21 @@
 //! ObjectId
 
-use libc;
-
 use std::sync::atomic::{AtomicUsize, Ordering, ATOMIC_USIZE_INIT};
 use std::{error, fmt, io, result};
 
 use byteorder::{BigEndian, ByteOrder, LittleEndian};
-use md5;
 
 use hex::{self, FromHexError};
 
 use rand::{thread_rng, Rng};
 
+#[cfg(not(target_arch = "wasm32"))]
 use hostname::get_hostname;
+#[cfg(not(target_arch = "wasm32"))]
+use libc;
+#[cfg(not(target_arch = "wasm32"))]
+use md5;
+
 use time;
 
 const TIMESTAMP_SIZE: usize = 4;
@@ -197,6 +200,7 @@ impl ObjectId {
 
     // Generates a new machine id represented as an MD5-hashed 3-byte-encoded hostname string.
     // Represented in Little Endian.
+    #[cfg(not(target_arch = "wasm32"))]
     fn gen_machine_id() -> Result<[u8; 3]> {
         // Short-circuit if machine id has already been calculated.
         // Since the generated machine id is not variable, arising race conditions
@@ -230,15 +234,43 @@ impl ObjectId {
         Ok(vec)
     }
 
+    // In case of wasm compilation generates a random 3-byte array.
+    #[cfg(target_arch = "wasm32")]
+    fn gen_machine_id() -> Result<[u8; 3]> {
+        // Short-circuit if machine id has already been calculated.
+        // Since the generated machine id is not variable, arising race conditions
+        // will have the same MACHINE_BYTES result.
+        unsafe {
+            if let Some(bytes) = MACHINE_BYTES.as_ref() {
+                return Ok(bytes.clone());
+            }
+        }
+
+        let mut rng = rand::thread_rng();
+        let vec: [u8; 3] = [rng.gen(), rng.gen(), rng.gen()];
+
+        unsafe { MACHINE_BYTES = Some(vec) };
+        Ok(vec)
+    }
+
     // Gets the process ID and returns it as a 2-byte array.
     // Represented in Little Endian.
+    #[cfg(not(target_arch = "wasm32"))]
     fn gen_process_id() -> [u8; 2] {
         let pid = unsafe { libc::getpid() as u16 };
         let mut buf: [u8; 2] = [0; 2];
         LittleEndian::write_u16(&mut buf, pid);
         buf
     }
 
+    // In case of wasm return a random 2-byte array.
+    #[cfg(target_arch = "wasm32")]
+    fn gen_process_id() -> [u8; 2] {
+        let mut rng = rand::thread_rng();
+        let vec: [u8; 2] = [rng.gen(), rng.gen()];
+        vec
+    }
+
     // Gets an incremental 3-byte count.
     // Represented in Big Endian.
     fn gen_count() -> Result<[u8; 3]> {
@@ -279,6 +311,7 @@ impl fmt::Debug for ObjectId {
 }
 
 #[test]
+#[cfg(not(target_arch = "wasm33"))]
 fn pid_generation() {
     let pid = unsafe { libc::getpid() as u16 };
     let generated = ObjectId::gen_process_id();