1 files changed, 266 insertions, 3 deletions

diff --git a/extensions/web/lib.rs b/extensions/web/lib.rs
index 7fa809776..2f2f15942 100644
--- a/extensions/web/lib.rs
+++ b/extensions/web/lib.rs
@@ -1,10 +1,28 @@
 // Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
 
+use deno_core::error::bad_resource_id;
+use deno_core::error::range_error;
+use deno_core::error::type_error;
 use deno_core::error::AnyError;
 use deno_core::include_js_files;
+use deno_core::op_sync;
 use deno_core::Extension;
+use deno_core::OpState;
+use deno_core::Resource;
+use deno_core::ResourceId;
+use deno_core::ZeroCopyBuf;
+use encoding_rs::CoderResult;
+use encoding_rs::Decoder;
+use encoding_rs::DecoderResult;
+use encoding_rs::Encoding;
+use serde::Deserialize;
+use serde::Serialize;
+
+use std::borrow::Cow;
+use std::cell::RefCell;
 use std::fmt;
 use std::path::PathBuf;
+use std::usize;
 
 /// Load and execute the javascript code.
 pub fn init() -> Extension {
@@ -17,12 +35,235 @@ pub fn init() -> Extension {
       "02_event.js",
       "03_abort_signal.js",
       "04_global_interfaces.js",
+      "05_base64.js",
       "08_text_encoding.js",
       "12_location.js",
     ))
+    .ops(vec![
+      ("op_base64_decode", op_sync(op_base64_decode)),
+      ("op_base64_encode", op_sync(op_base64_encode)),
+      (
+        "op_encoding_normalize_label",
+        op_sync(op_encoding_normalize_label),
+      ),
+      ("op_encoding_new_decoder", op_sync(op_encoding_new_decoder)),
+      ("op_encoding_decode", op_sync(op_encoding_decode)),
+      ("op_encoding_encode_into", op_sync(op_encoding_encode_into)),
+    ])
     .build()
 }
 
+fn op_base64_decode(
+  _state: &mut OpState,
+  input: String,
+  _: (),
+) -> Result<ZeroCopyBuf, AnyError> {
+  let mut input: &str = &input.replace(|c| char::is_ascii_whitespace(&c), "");
+  // "If the length of input divides by 4 leaving no remainder, then:
+  //  if input ends with one or two U+003D EQUALS SIGN (=) characters,
+  //  remove them from input."
+  if input.len() % 4 == 0 {
+    if input.ends_with("==") {
+      input = &input[..input.len() - 2]
+    } else if input.ends_with('=') {
+      input = &input[..input.len() - 1]
+    }
+  }
+
+  // "If the length of input divides by 4 leaving a remainder of 1,
+  //  throw an InvalidCharacterError exception and abort these steps."
+  if input.len() % 4 == 1 {
+    return Err(
+      DomExceptionInvalidCharacterError::new("Failed to decode base64.").into(),
+    );
+  }
+
+  if input
+    .chars()
+    .any(|c| c != '+' && c != '/' && !c.is_alphanumeric())
+  {
+    return Err(
+      DomExceptionInvalidCharacterError::new(
+        "Failed to decode base64: invalid character",
+      )
+      .into(),
+    );
+  }
+
+  let cfg = base64::Config::new(base64::CharacterSet::Standard, true)
+    .decode_allow_trailing_bits(true);
+  let out = base64::decode_config(&input, cfg).map_err(|err| {
+    DomExceptionInvalidCharacterError::new(&format!(
+      "Failed to decode base64: {:?}",
+      err
+    ))
+  })?;
+  Ok(ZeroCopyBuf::from(out))
+}
+
+fn op_base64_encode(
+  _state: &mut OpState,
+  s: ZeroCopyBuf,
+  _: (),
+) -> Result<String, AnyError> {
+  let cfg = base64::Config::new(base64::CharacterSet::Standard, true)
+    .decode_allow_trailing_bits(true);
+  let out = base64::encode_config(&s, cfg);
+  Ok(out)
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct DecoderOptions {
+  label: String,
+  ignore_bom: bool,
+  fatal: bool,
+}
+
+fn op_encoding_normalize_label(
+  _state: &mut OpState,
+  label: String,
+  _: (),
+) -> Result<String, AnyError> {
+  let encoding = Encoding::for_label_no_replacement(label.as_bytes())
+    .ok_or_else(|| {
+      range_error(format!(
+        "The encoding label provided ('{}') is invalid.",
+        label
+      ))
+    })?;
+  Ok(encoding.name().to_lowercase())
+}
+
+fn op_encoding_new_decoder(
+  state: &mut OpState,
+  options: DecoderOptions,
+  _: (),
+) -> Result<ResourceId, AnyError> {
+  let DecoderOptions {
+    label,
+    fatal,
+    ignore_bom,
+  } = options;
+
+  let encoding = Encoding::for_label(label.as_bytes()).ok_or_else(|| {
+    range_error(format!(
+      "The encoding label provided ('{}') is invalid.",
+      label
+    ))
+  })?;
+
+  let decoder = if ignore_bom {
+    encoding.new_decoder_without_bom_handling()
+  } else {
+    encoding.new_decoder_with_bom_removal()
+  };
+
+  let rid = state.resource_table.add(TextDecoderResource {
+    decoder: RefCell::new(decoder),
+    fatal,
+  });
+
+  Ok(rid)
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct DecodeOptions {
+  rid: ResourceId,
+  stream: bool,
+}
+
+fn op_encoding_decode(
+  state: &mut OpState,
+  data: ZeroCopyBuf,
+  options: DecodeOptions,
+) -> Result<String, AnyError> {
+  let DecodeOptions { rid, stream } = options;
+
+  let resource = state
+    .resource_table
+    .get::<TextDecoderResource>(rid)
+    .ok_or_else(bad_resource_id)?;
+
+  let mut decoder = resource.decoder.borrow_mut();
+  let fatal = resource.fatal;
+
+  let max_buffer_length = if fatal {
+    decoder
+      .max_utf8_buffer_length_without_replacement(data.len())
+      .ok_or_else(|| range_error("Value too large to decode."))?
+  } else {
+    decoder
+      .max_utf8_buffer_length(data.len())
+      .ok_or_else(|| range_error("Value too large to decode."))?
+  };
+
+  let mut output = String::with_capacity(max_buffer_length);
+
+  if fatal {
+    let (result, _) =
+      decoder.decode_to_string_without_replacement(&data, &mut output, !stream);
+    match result {
+      DecoderResult::InputEmpty => Ok(output),
+      DecoderResult::OutputFull => {
+        Err(range_error("Provided buffer too small."))
+      }
+      DecoderResult::Malformed(_, _) => {
+        Err(type_error("The encoded data is not valid."))
+      }
+    }
+  } else {
+    let (result, _, _) = decoder.decode_to_string(&data, &mut output, !stream);
+    match result {
+      CoderResult::InputEmpty => Ok(output),
+      CoderResult::OutputFull => Err(range_error("Provided buffer too small.")),
+    }
+  }
+}
+
+struct TextDecoderResource {
+  decoder: RefCell<Decoder>,
+  fatal: bool,
+}
+
+impl Resource for TextDecoderResource {
+  fn name(&self) -> Cow<str> {
+    "textDecoder".into()
+  }
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct EncodeIntoResult {
+  read: usize,
+  written: usize,
+}
+
+fn op_encoding_encode_into(
+  _state: &mut OpState,
+  input: String,
+  mut buffer: ZeroCopyBuf,
+) -> Result<EncodeIntoResult, AnyError> {
+  let dst: &mut [u8] = &mut buffer;
+  let mut read = 0;
+  let mut written = 0;
+  for char in input.chars() {
+    let len = char.len_utf8();
+    if dst.len() < written + len {
+      break;
+    }
+    char.encode_utf8(&mut dst[written..]);
+    written += len;
+    if char > '\u{FFFF}' {
+      read += 2
+    } else {
+      read += 1
+    };
+  }
+  Ok(EncodeIntoResult { read, written })
+}
+
 pub fn get_declaration() -> PathBuf {
   PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("lib.deno_web.d.ts")
 }
@@ -40,17 +281,39 @@ impl DomExceptionQuotaExceededError {
   }
 }
 
+#[derive(Debug)]
+pub struct DomExceptionInvalidCharacterError {
+  pub msg: String,
+}
+
+impl DomExceptionInvalidCharacterError {
+  pub fn new(msg: &str) -> Self {
+    DomExceptionInvalidCharacterError {
+      msg: msg.to_string(),
+    }
+  }
+}
+
 impl fmt::Display for DomExceptionQuotaExceededError {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
     f.pad(&self.msg)
   }
 }
+impl fmt::Display for DomExceptionInvalidCharacterError {
+  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    f.pad(&self.msg)
+  }
+}
 
 impl std::error::Error for DomExceptionQuotaExceededError {}
 
-pub fn get_quota_exceeded_error_class_name(
-  e: &AnyError,
-) -> Option<&'static str> {
+impl std::error::Error for DomExceptionInvalidCharacterError {}
+
+pub fn get_error_class_name(e: &AnyError) -> Option<&'static str> {
   e.downcast_ref::<DomExceptionQuotaExceededError>()
     .map(|_| "DOMExceptionQuotaExceededError")
+    .or_else(|| {
+      e.downcast_ref::<DomExceptionInvalidCharacterError>()
+        .map(|_| "DOMExceptionInvalidCharacterError")
+    })
 }