update response namespace

src/client/connection/response/meta/data.rs

@@ -0,0 +1,61 @@
+//! Components for reading and parsing meta **data** bytes from response
+//! (e.g. placeholder text for 10, 11, url string for 30, 31 etc)
+
+pub mod error;
+pub use error::Error;
+
+use glib::GString;
+
+/// Meta **data** holder
+///
+/// For example, `value` could contain:
+/// * placeholder text for 10, 11 status
+/// * URL string for 30, 31 status
+pub struct Data {
+    pub value: GString,
+}
+
+impl Data {
+    // Constructors
+
+    /// Parse meta **data** from UTF-8 buffer
+    /// from entire response or just header slice
+    ///
+    /// * result could be `None` for some [status codes](https://geminiprotocol.net/docs/protocol-specification.gmi#status-codes)
+    ///   that does not expect any data in header
+    pub fn from_utf8(buffer: &[u8]) -> Result<Option<Self>, Error> {
+        // Define max buffer length for this method
+        const MAX_LEN: usize = 0x400; // 1024
+
+        // Init bytes buffer
+        let mut bytes: Vec<u8> = Vec::with_capacity(MAX_LEN);
+
+        // Calculate len once
+        let len = buffer.len();
+
+        // Skip 3 bytes for status code of `MAX_LEN` expected
+        match buffer.get(3..if len > MAX_LEN { MAX_LEN - 3 } else { len }) {
+            Some(slice) => {
+                for &byte in slice {
+                    // End of header
+                    if byte == b'\r' {
+                        break;
+                    }
+
+                    // Continue
+                    bytes.push(byte);
+                }
+
+                // Assumes the bytes are valid UTF-8
+                match GString::from_utf8(bytes) {
+                    Ok(value) => Ok(match value.is_empty() {
+                        false => Some(Self { value }),
+                        true => None,
+                    }),
+                    Err(e) => Err(Error::Decode(e)),
+                }
+            }
+            None => Err(Error::Protocol),
+        }
+    }
+}