1 files changed, 145 insertions, 0 deletions
diff --git a/src/archive.rs b/src/archive.rs
new file mode 100644
index 0000000..206d252
--- /dev/null
+++ b/src/archive.rs
@@ -0,0 +1,145 @@
+use actix_web::http::ContentEncoding;
+use bytes::Bytes;
+use failure::ResultExt;
+use libflate::gzip::Encoder;
+use serde::Deserialize;
+use std::io;
+use std::path::PathBuf;
+use tar::Builder;
+
+use crate::errors;
+
+/// Available compression methods
+#[derive(Debug, Deserialize, Clone)]
+pub enum CompressionMethod {
+    /// TAR GZ
+    #[serde(alias = "targz")]
+    TarGz,
+}
+
+impl CompressionMethod {
+    pub fn to_string(&self) -> String {
+        match &self {
+            CompressionMethod::TarGz => "targz",
+        }
+        .to_string()
+    }
+
+    pub fn extension(&self) -> String {
+        match &self {
+            CompressionMethod::TarGz => "tar.gz",
+        }
+        .to_string()
+    }
+
+    pub fn content_type(&self) -> String {
+        match &self {
+            CompressionMethod::TarGz => "application/gzip",
+        }
+        .to_string()
+    }
+
+    pub fn content_encoding(&self) -> ContentEncoding {
+        match &self {
+            CompressionMethod::TarGz => ContentEncoding::Gzip,
+        }
+    }
+}
+
+/// Creates an archive of a folder, using the algorithm the user chose from the web interface
+/// This method returns the archive as a stream of bytes
+pub fn create_archive(
+    method: &CompressionMethod,
+    dir: &PathBuf,
+    skip_symlinks: bool,
+) -> Result<(String, Bytes), errors::CompressionError> {
+    match method {
+        CompressionMethod::TarGz => tgz_compress(&dir, skip_symlinks),
+    }
+}
+
+/// Compresses a given folder in .tar.gz format, and returns the result as a stream of bytes
+fn tgz_compress(
+    dir: &PathBuf,
+    skip_symlinks: bool,
+) -> Result<(String, Bytes), errors::CompressionError> {
+    let src_dir = dir.display().to_string();
+    let inner_folder = match dir.file_name() {
+        Some(directory_name) => match directory_name.to_str() {
+            Some(directory) => directory,
+            None => {
+                return Err(errors::CompressionError::new(
+                    errors::CompressionErrorKind::InvalidUTF8DirectoryName,
+                ))
+            }
+        },
+        None => {
+            return Err(errors::CompressionError::new(
+                errors::CompressionErrorKind::InvalidDirectoryName,
+            ))
+        }
+    };
+    let dst_filename = format!("{}.tar", inner_folder);
+    let dst_tgz_filename = format!("{}.gz", dst_filename);
+
+    let tar_content = tar(src_dir, inner_folder.to_string(), skip_symlinks).context(
+        errors::CompressionErrorKind::TarBuildingError {
+            message: "an error occured while writing the TAR archive".to_string(),
+        },
+    )?;
+    let gz_data = gzip(&tar_content).context(errors::CompressionErrorKind::GZipBuildingError {
+        message: "an error occured while writing the GZIP archive".to_string(),
+    })?;
+
+    let mut data = Bytes::new();
+    data.extend_from_slice(&gz_data);
+
+    Ok((dst_tgz_filename, data))
+}
+
+/// Creates a TAR archive of a folder, and returns it as a stream of bytes
+fn tar(
+    src_dir: String,
+    inner_folder: String,
+    skip_symlinks: bool,
+) -> Result<Vec<u8>, errors::CompressionError> {
+    let mut tar_builder = Builder::new(Vec::new());
+
+    tar_builder.follow_symlinks(!skip_symlinks);
+    // Recursively adds the content of src_dir into the archive stream
+    tar_builder.append_dir_all(inner_folder, &src_dir).context(
+        errors::CompressionErrorKind::TarBuildingError {
+            message: format!(
+                "failed to append the content of {} to the TAR archive",
+                &src_dir
+            ),
+        },
+    )?;
+
+    let tar_content =
+        tar_builder
+            .into_inner()
+            .context(errors::CompressionErrorKind::TarBuildingError {
+                message: "failed to finish writing the TAR archive".to_string(),
+            })?;
+
+    Ok(tar_content)
+}
+
+/// Compresses a stream of bytes using the GZIP algorithm, and returns the resulting stream
+fn gzip(mut data: &[u8]) -> Result<Vec<u8>, errors::CompressionError> {
+    let mut encoder =
+        Encoder::new(Vec::new()).context(errors::CompressionErrorKind::GZipBuildingError {
+            message: "failed to create GZIP encoder".to_string(),
+        })?;
+    io::copy(&mut data, &mut encoder).context(errors::CompressionErrorKind::GZipBuildingError {
+        message: "failed to write GZIP data".to_string(),
+    })?;
+    let data = encoder.finish().into_result().context(
+        errors::CompressionErrorKind::GZipBuildingError {
+            message: "failed to write GZIP trailer".to_string(),
+        },
+    )?;
+
+    Ok(data)
+}