feat: implement HttpHead as new RADType

data_structures/src/chain/mod.rs

@@ -1645,11 +1645,14 @@ pub enum RADType {
     /// HTTP POST request
     #[serde(rename = "HTTP-POST")]
     HttpPost,
+    /// HTTP HEAD request
+    #[serde(rename = "HTTP-HEAD")]
+    HttpHead,
 }
 
 impl RADType {
     pub fn is_http(&self) -> bool {
-        matches!(self, RADType::HttpGet | RADType::HttpPost)
+        matches!(self, RADType::HttpGet | RADType::HttpPost | RADType::HttpHead)
     }
 }
 
@@ -1701,7 +1704,7 @@ pub struct RADRetrieve {
     pub script: Vec<u8>,
     /// Body of a HTTP-POST request
     pub body: Vec<u8>,
-    /// Extra headers of a HTTP-GET or HTTP-POST request
+    /// Extra headers of a HTTP-GET, HTTP-POST or HTTP-HEAD request
     pub headers: Vec<(String, String)>,
 }
 
@@ -1809,7 +1812,8 @@ impl RADRetrieve {
                     &[Field::Kind, Field::Url, Field::Script],
                     &[Field::Body, Field::Headers],
                 )
-            }
+            },
+            RADType::HttpHead => check(&[Field::Kind, Field::Url, Field::Script], &[Field::Headers])
         }
     }
 

data_structures/src/proto/mod.rs

@@ -51,6 +51,7 @@ impl ProtobufConvert for chain::RADType {
             chain::RADType::HttpGet => witnet::DataRequestOutput_RADRequest_RADType::HttpGet,
             chain::RADType::Rng => witnet::DataRequestOutput_RADRequest_RADType::Rng,
             chain::RADType::HttpPost => witnet::DataRequestOutput_RADRequest_RADType::HttpPost,
+            chain::RADType::HttpHead => witnet::DataRequestOutput_RADRequest_RADType::HttpHead,
         }
     }
 
@@ -60,6 +61,7 @@ impl ProtobufConvert for chain::RADType {
             witnet::DataRequestOutput_RADRequest_RADType::HttpGet => chain::RADType::HttpGet,
             witnet::DataRequestOutput_RADRequest_RADType::Rng => chain::RADType::Rng,
             witnet::DataRequestOutput_RADRequest_RADType::HttpPost => chain::RADType::HttpPost,
+            witnet::DataRequestOutput_RADRequest_RADType::HttpHead => chain::RADType::HttpHead,
         })
     }
 }

data_structures/src/serialization_helpers.rs

@@ -360,7 +360,7 @@ struct RADRetrieveSerializationHelperJson {
     /// Body of a HTTP-POST request
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub body: Vec<u8>,
-    /// Extra headers of a HTTP-GET or HTTP-POST request
+    /// Extra headers of a HTTP-GET, HTTP-HEAD or HTTP-POST request
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub headers: Vec<(String, String)>,
 }
@@ -377,7 +377,7 @@ struct RADRetrieveSerializationHelperBincode {
     pub script: Vec<u8>,
     /// Body of a HTTP-POST request
     pub body: Vec<u8>,
-    /// Extra headers of a HTTP-GET or HTTP-POST request
+    /// Extra headers of a HTTP-GET, HTTP-HEAD or HTTP-POST request
     pub headers: Vec<(String, String)>,
 }
 

rad/src/lib.rs

@@ -25,10 +25,11 @@ use crate::{
         create_radon_script_from_filters_and_reducer, execute_radon_script, unpack_radon_script,
         RadonScriptExecutionSettings,
     },
-    types::{array::RadonArray, bytes::RadonBytes, string::RadonString, RadonTypes},
+    types::{array::RadonArray, bytes::RadonBytes, string::RadonString, map::RadonMap, RadonTypes},
     user_agents::UserAgent,
 };
 use core::convert::From;
+use std::collections::BTreeMap;
 use witnet_net::client::http::{WitnetHttpBody, WitnetHttpRequest};
 
 pub mod conditions;
@@ -173,6 +174,25 @@ fn string_response_with_data_report(
     execute_radon_script(input, &radon_script, context, settings)
 }
 
+/// Handle HTTP-HEAD response with data, and return a `RadonReport`.
+fn headers_response_with_data_report(
+    retrieve: &RADRetrieve,
+    response: &str,
+    context: &mut ReportContext<RadonTypes>,
+    settings: RadonScriptExecutionSettings,
+) -> Result<RadonReport<RadonTypes>> {
+    let headers: BTreeMap<String, RadonTypes> = response.split("\r\n").map(|line| {
+       let parts: Vec<&str> = line.split(":").map(|part| part.trim()).collect();
+        // todo: check there are two parts, and two parts only
+        // todo: make sure that values from repeated keys get appended within a RadonArray
+        (String::from(parts[0]), RadonTypes::from(RadonString::from(parts[1])))
+    }).collect();
+    let input = RadonTypes::from(RadonMap::from(headers));
+    let radon_script = unpack_radon_script(&retrieve.script)?;
+
+    execute_radon_script(input, &radon_script, context, settings)
+}
+
 /// Handle Rng response with data report
 fn rng_response_with_data_report(
     response: &str,
@@ -196,7 +216,10 @@ pub fn run_retrieval_with_data_report(
         RADType::Rng => rng_response_with_data_report(response, context),
         RADType::HttpPost => {
             string_response_with_data_report(retrieve, response, context, settings)
-        }
+        },
+        RADType::HttpHead => {
+            headers_response_with_data_report(retrieve, response, context, settings)
+        },
         _ => Err(RadError::UnknownRetrieval),
     }
 }
@@ -214,7 +237,7 @@ pub fn run_retrieval_with_data(
         .map(RadonReport::into_inner)
 }
 
-/// Handle generic HTTP (GET/POST) response
+/// Handle generic HTTP (GET/POST/HEAD) response
 async fn http_response(
     retrieve: &RADRetrieve,
     context: &mut ReportContext<RadonTypes>,
@@ -258,7 +281,11 @@ async fn http_response(
                     builder.method("POST").uri(&retrieve.url),
                     WitnetHttpBody::from(retrieve.body.clone()),
                 )
-            }
+            },
+            RADType::HttpHead => (
+                builder.method("HEAD").uri(&retrieve.url),
+                WitnetHttpBody::empty(),
+            ),
             _ => panic!(
                 "Called http_response with invalid retrieval kind {:?}",
                 retrieve.kind
@@ -357,6 +384,7 @@ pub async fn run_retrieval_report(
         RADType::HttpGet => http_response(retrieve, context, settings, client).await,
         RADType::Rng => rng_response(context, settings).await,
         RADType::HttpPost => http_response(retrieve, context, settings, client).await,
+        RADType::HttpHead => http_response(retrieve, context, settings, client).await,
         _ => Err(RadError::UnknownRetrieval),
     }
 }

schemas/witnet/witnet.proto

@@ -121,6 +121,7 @@ message DataRequestOutput {
             HttpGet = 1;
             Rng = 2;
             HttpPost = 3;
+            HttpHead = 4;
         }
         message RADFilter {
             uint32 op = 1;
@@ -133,7 +134,7 @@ message DataRequestOutput {
             bytes script = 3;
             // Body of HTTP-POST request
             bytes body = 4;
-            // Extra headers for HTTP-GET and HTTP-POST requests
+            // Extra headers for HTTP-GET, HTTP-HEAD and HTTP-POST requests
             repeated StringPair headers = 5;
         }
         message RADAggregate {