Create context objects.

  - Context objects can be used to tweak the library configuration.
    Currently, a home and lib directory can be set.  Reasonable
    defaults are provided.

  - Add ffi functions.

1 files changed, 65 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 079b6713..5530361e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,3 +16,68 @@ pub mod key_store;
 pub mod net;
 pub mod ffi;
 pub mod armor;
+
+use std::env;
+use std::fs;
+use std::io;
+use std::path::{Path, PathBuf};
+
+/// A `&Context` is required for many operations.
+pub struct Context {
+    home: PathBuf,
+    lib: PathBuf,
+}
+
+fn prefix() -> PathBuf {
+    /* XXX: Windows support.  */
+    PathBuf::from(option_env!("PREFIX").or(Some("/usr/local")).unwrap())
+}
+
+impl Context {
+    /// Create a `Pre(Context)` with reasonable defaults.  `Pre(Context)`s
+    /// can be modified, and have to be finalized in order to turn
+    /// them into a Context.
+    pub fn new() -> Pre {
+        Pre(Context {
+            home: env::home_dir().unwrap_or(env::temp_dir())
+                .join(".sequoia"),
+            lib: prefix().join("lib").join("sequoia"),
+        })
+    }
+
+    /// Return the directory containing shared state and rendezvous
+    /// nodes.
+    pub fn home(&self) -> &Path {
+        &self.home
+    }
+
+    /// Return the directory containing backend servers.
+    pub fn lib(&self) -> &Path {
+        &self.lib
+    }
+}
+
+/// A `Pre(Context)` is a context object that can be modified.
+pub struct Pre(Context);
+
+impl Pre {
+    /// Finalize the configuration and return a `Context`.
+    pub fn finalize(self) -> io::Result<Context> {
+        let c = self.0;
+        fs::create_dir_all(c.home())?;
+        Ok(c)
+    }
+
+    /// Set the directory containing shared state and rendezvous
+    /// nodes.
+    pub fn home<P: AsRef<Path>>(mut self, new: P) -> Self {
+        self.0.home = PathBuf::new().join(new);
+        self
+    }
+
+    /// Set the directory containing backend servers.
+    pub fn lib<P: AsRef<Path>>(mut self, new: P) -> Self {
+        self.0.lib = PathBuf::new().join(new);
+        self
+    }
+}