fix: remove dependency on regex to reduce wasm size

Cargo.toml

@@ -34,10 +34,10 @@ bytes = "1"
 base64 = "0.22"
 lazy_static = "1"
 rand_chacha = "0.3"
-regex = "1"
 serde = "1"
 serde_cbor = "0.11"
 sha2 = "0.10"
+text_io = "0.1"
 tokio = { version = "1", features = ["full"] }
 hyper = { version = "1", features = ["full"] }
 hyper-util = "0.1"

examples/http-gateway/canister/src/custom_assets/Cargo.toml

@@ -11,10 +11,10 @@ candid.workspace = true
 http.workspace = true
 ic-cdk.workspace = true
 ic-cdk-macros.workspace = true
-regex.workspace = true
 serde.workspace = true
 serde_cbor.workspace = true
 sha2.workspace = true
+text_io.workspace = true
 lazy_static.workspace = true
 base64.workspace = true
 include_dir = { version = "0.7", features = ["glob"] }

examples/http-gateway/canister/src/custom_assets/src/lib.rs

@@ -9,6 +9,7 @@ use ic_http_certification::{
 use rand_chacha::rand_core::{RngCore, SeedableRng};
 use rand_chacha::ChaCha20Rng;
 use std::cell::RefCell;
+use text_io::try_scan;
 
 #[init]
 fn init() {
@@ -162,15 +163,16 @@ fn get_header_value(headers: &[HeaderField], header_name: &str) -> Option<String
 
 fn get_content_range_begin(content_range_header_value: &str) -> usize {
     // expected format: `bytes 21010-47021/47022`
-    let re = regex::Regex::new(r"bytes\s+(\d+)-(\d+)/(\d+)").expect("invalid RE");
-    let caps = re
-        .captures(content_range_header_value)
-        .expect("malformed Content-Range header");
-    caps.get(1)
-        .expect("missing range-begin")
-        .as_str()
-        .parse()
-        .expect("malformed range-begin")
+    fn parse(value: &str) -> Result<(usize, usize, usize), Box<dyn std::error::Error>> {
+        let (range_begin, range_end, total_length);
+        try_scan!(value.bytes() => "bytes {}-{}/{}", range_begin, range_end, total_length);
+        Ok((range_begin, range_end, total_length))
+    }
+    let parsed = parse(content_range_header_value).expect(&format!(
+        "invalid Content-Range header: {}",
+        content_range_header_value
+    ));
+    parsed.0
 }
 
 thread_local! {

packages/ic-http-gateway/Cargo.toml

@@ -26,7 +26,7 @@ http.workspace = true
 http-body.workspace = true
 http-body-util.workspace = true
 bytes.workspace = true
-regex.workspace = true
+text_io.workspace = true
 
 ic-agent.workspace = true
 ic-utils.workspace = true

packages/ic-http-gateway/src/response/response_handler.rs

@@ -16,7 +16,7 @@ use ic_utils::{
         StreamingCallbackHttpResponse, StreamingStrategy, Token,
     },
 };
-use regex::Regex;
+use text_io::try_scan;
 
 // Limit the total number of calls to an HTTP Request loop to 1000 for now.
 static MAX_HTTP_REQUEST_STREAM_CALLBACK_CALL_COUNT: usize = 1000;
@@ -177,42 +177,29 @@ struct ContentRangeValues {
 
 fn parse_content_range_header_str(str_value: &str) -> Result<ContentRangeValues, AgentError> {
     // expected format: `bytes 21010-47021/47022`
-    let re = Regex::new(r"bytes\s+(\d+)-(\d+)/(\d+)").unwrap();
-    let Some(caps) = re.captures(str_value) else {
-        return Err(AgentError::InvalidHttpResponse(
-            "malformed Content-Range header".to_string(),
-        ));
-    };
-    let range_begin: usize = caps
-        .get(1)
-        .ok_or_else(|| AgentError::InvalidHttpResponse("missing range-begin".to_string()))?
-        .as_str()
-        .parse()
-        .map_err(|_| AgentError::InvalidHttpResponse("malformed range-begin".to_string()))?;
-    let range_end: usize = caps
-        .get(2)
-        .ok_or_else(|| AgentError::InvalidHttpResponse("missing range-end".to_string()))?
-        .as_str()
-        .parse()
-        .map_err(|_| AgentError::InvalidHttpResponse("malformed range-end".to_string()))?;
-    let total_length: usize = caps
-        .get(3)
-        .ok_or_else(|| AgentError::InvalidHttpResponse("missing size".to_string()))?
-        .as_str()
-        .parse()
-        .map_err(|_| AgentError::InvalidHttpResponse("malformed size".to_string()))?;
-    let range_values = ContentRangeValues {
-        range_begin,
-        range_end,
-        total_length,
+    fn parse(value: &str) -> Result<(usize, usize, usize), Box<dyn std::error::Error>> {
+        let (range_begin, range_end, total_length);
+        try_scan!(value.bytes() => "bytes {}-{}/{}", range_begin, range_end, total_length);
+        Ok((range_begin, range_end, total_length))
+    }
+    let parsed = parse(str_value).map_err(|e| {
+        AgentError::InvalidHttpResponse(format!("malformed Content-Range header: {:?}", e))
+    })?;
+    let rv = ContentRangeValues {
+        range_begin: parsed.0,
+        range_end: parsed.1,
+        total_length: parsed.2,
     };
-    if range_begin > range_end || range_begin >= total_length || range_end >= total_length {
+    if rv.range_begin > rv.range_end
+        || rv.range_begin >= rv.total_length
+        || rv.range_end >= rv.total_length
+    {
         Err(AgentError::InvalidHttpResponse(format!(
             "inconsistent Content-Range header {:?}",
-            range_values
+            rv
         )))
     } else {
-        Ok(range_values)
+        Ok(rv)
     }
 }