add new constructors, add read_input_stream_async method, change read_input_stream api

src/client/connection/input_stream/byte_buffer.rs

@@ -3,7 +3,7 @@ pub mod error;
 pub use error::Error;
 
 use gio::{prelude::InputStreamExt, Cancellable, InputStream};
-use glib::{object::IsA, Bytes};
+use glib::{object::IsA, Bytes, Priority};
 
 pub const DEFAULT_CAPACITY: usize = 0x400;
 pub const DEFAULT_CHUNK_SIZE: usize = 0x100;
@@ -14,25 +14,42 @@ pub struct ByteBuffer {
 }
 
 impl ByteBuffer {
-    /// Create dynamically allocated bytes buffer from `gio::InputStream`
+    // Constructors
+
+    /// Create new dynamically allocated bytes buffer with default capacity
+    pub fn new() -> Self {
+        Self::with_capacity(Some(DEFAULT_CAPACITY))
+    }
+
+    /// Create new dynamically allocated bytes buffer with initial capacity
     ///
     /// Options:
-    /// * `capacity` bytes request to reduce extra memory overwrites (1024 by default)
+    /// * initial bytes request to reduce extra memory overwrites (1024 by default)
+    pub fn with_capacity(value: Option<usize>) -> Self {
+        Self {
+            bytes: Vec::with_capacity(match value {
+                Some(capacity) => capacity,
+                None => DEFAULT_CAPACITY,
+            }),
+        }
+    }
+
+    // Readers
+
+    /// Populate bytes buffer synchronously from `gio::InputStream`
+    ///
+    /// Options:
+    /// * `input_stream` https://docs.gtk.org/gio/class.InputStream.html
+    /// * `cancellable` https://docs.gtk.org/gio/class.Cancellable.html
     /// * `chunk_size` bytes limit to read per iter (256 by default)
     /// * `max_size` bytes limit to prevent memory overflow (1M by default)
-    pub fn from_input_stream(
-        input_stream: &InputStream, // @TODO
+    pub fn read_input_stream(
+        mut self,
+        input_stream: InputStream,
         cancellable: Option<&impl IsA<Cancellable>>,
-        capacity: Option<usize>,
         chunk_size: Option<usize>,
         max_size: Option<usize>,
     ) -> Result<Self, Error> {
-        // Create buffer with initial capacity
-        let mut buffer: Vec<Bytes> = Vec::with_capacity(match capacity {
-            Some(value) => value,
-            None => DEFAULT_CAPACITY,
-        });
-
         // Disallow unlimited buffer, use defaults on None
         let limit = match max_size {
             Some(value) => value,
@@ -41,7 +58,7 @@ impl ByteBuffer {
 
         loop {
             // Check buffer size to prevent memory overflow
-            if buffer.len() > limit {
+            if self.bytes.len() > limit {
                 return Err(Error::Overflow);
             }
 
@@ -56,18 +73,73 @@ impl ByteBuffer {
                 Ok(bytes) => {
                     // No bytes were read, end of stream
                     if bytes.len() == 0 {
-                        break;
+                        return Ok(self);
                     }
 
                     // Save chunk to buffer
-                    buffer.push(bytes);
+                    self.bytes.push(bytes);
                 }
-                Err(_) => return Err(Error::Stream),
+                Err(_) => return Err(Error::StreamChunkRead),
             };
         }
+    }
 
-        // Done
-        Ok(Self { bytes: buffer })
+    /// Populate bytes buffer asynchronously from `gio::InputStream`,
+    /// apply callback function to `Ok(Self)` on success
+    ///
+    /// Options:
+    /// * `input_stream` https://docs.gtk.org/gio/class.InputStream.html
+    /// * `cancellable` https://docs.gtk.org/gio/class.Cancellable.html
+    /// * `priority` e.g. https://docs.gtk.org/glib/const.PRIORITY_DEFAULT.html
+    /// * `chunk_size` optional bytes limit to read per iter (256 by default)
+    /// * `max_size` optional bytes limit to prevent memory overflow (1M by default)
+    /// * `callback` user function to apply on complete
+    pub fn read_input_stream_async(
+        mut self,
+        input_stream: InputStream,
+        cancellable: Cancellable,
+        priority: Priority,
+        chunk_size: Option<usize>,
+        max_size: Option<usize>,
+        callback: impl FnOnce(Result<Self, Error>) + 'static,
+    ) {
+        // Clone reference counted chunk dependencies
+        let _input_stream = input_stream.clone();
+        let _cancellable = cancellable.clone();
+
+        // Continue bytes reading
+        input_stream.read_bytes_async(
+            match max_size {
+                Some(value) => value,
+                None => DEFAULT_MAX_SIZE,
+            },
+            priority,
+            Some(&cancellable),
+            move |result| -> () {
+                match result {
+                    Ok(bytes) => {
+                        // No bytes were read, end of stream
+                        if bytes.len() == 0 {
+                            return callback(Ok(self));
+                        }
+
+                        // Save chunk to buffer
+                        self.bytes.push(bytes);
+
+                        // Continue bytes reading...
+                        self.read_input_stream_async(
+                            _input_stream,
+                            _cancellable,
+                            priority,
+                            chunk_size,
+                            max_size,
+                            callback,
+                        );
+                    }
+                    Err(_) => callback(Err(Error::StreamChunkReadAsync)),
+                }
+            },
+        );
     }
 
     /// Get link to bytes collected

src/client/connection/input_stream/byte_buffer/error.rs

@@ -1,4 +1,5 @@
 pub enum Error {
     Overflow,
-    Stream,
+    StreamChunkRead,
+    StreamChunkReadAsync,
 }