Add config serialize ability

1 files changed, 611 insertions, 0 deletions

diff --git a/src/ser.rs b/src/ser.rs
new file mode 100644
index 0000000..7ea1a43
--- /dev/null
+++ b/src/ser.rs
@@ -0,0 +1,611 @@
+use std::mem;
+use std::fmt::Display;
+use serde::ser;
+
+use Config;
+use value::{Value, ValueKind, ValueWithKey};
+use error::*;
+
+#[derive(Default, Debug)]
+pub struct ConfigSerializer {
+    keys: Vec<(String, Option<usize>)>,
+    pub output: Config,
+}
+
+impl ConfigSerializer {
+    fn serialize_primitive<T>(&mut self, value: T) -> Result<()>
+        where T: Into<Value> + Display
+    {
+        let key = match self.last_key_index_pair() {
+            Some((key, Some(index))) => format!("{}[{}]", key, index),
+            Some((key, None)) => key.to_string(),
+            None => return Err(ConfigError::Message(format!("key is not found for value {}", value)))
+        };
+        self.output.set(&key, value.into())?;
+        Ok(())
+    }
+
+    fn last_key_index_pair(&self) -> Option<(&str, Option<usize>)> {
+        let len = self.keys.len();
+        if len > 0 {
+            self.keys.get(len - 1)
+                .map(|&(ref key, opt)| (key.as_str(), opt))
+        } else {
+            None
+        }
+    }
+
+    fn inc_last_key_index(&mut self) -> Result<()> {
+        let len = self.keys.len();
+        if len > 0 {
+            self.keys.get_mut(len - 1)
+                .map(|pair| {
+                    pair.1 = pair.1.map(|i| i + 1).or(Some(0))
+                })
+                .ok_or(ConfigError::Message(
+                    format!("last key is not found in {} keys", len)
+                ))
+        } else {
+            Err(ConfigError::Message("keys is empty".to_string()))
+        }
+    }
+
+    fn make_full_key(&self, key: &str) -> String {
+        let len = self.keys.len();
+        if len > 0 {
+            if let Some(&(ref prev_key, index)) = self.keys.get(len - 1) {
+                return if let Some(index) = index {
+                    format!("{}[{}].{}", prev_key, index, key)
+                } else {
+                    format!("{}.{}", prev_key, key)
+                }
+            }
+        }
+        key.to_string()
+    }
+
+    fn push_key(&mut self, key: &str) {
+        let full_key = self.make_full_key(key);
+        self.keys.push((full_key, None));
+    }
+
+    fn pop_key(&mut self) -> Option<(String, Option<usize>)> {
+        self.keys.pop()
+    }
+}
+
+impl<'a> ser::Serializer for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+    type SerializeSeq = Self;
+    type SerializeTuple = Self;
+    type SerializeTupleStruct = Self;
+    type SerializeTupleVariant = Self;
+    type SerializeMap = Self;
+    type SerializeStruct = Self;
+    type SerializeStructVariant = Self;
+
+    fn serialize_bool(self, v: bool) -> Result<Self::Ok> {
+        self.serialize_primitive(v)
+    }
+
+    fn serialize_i8(self, v: i8) -> Result<Self::Ok> {
+        self.serialize_i64(v as i64)
+    }
+
+    fn serialize_i16(self, v: i16) -> Result<Self::Ok> {
+        self.serialize_i64(v as i64)
+    }
+
+    fn serialize_i32(self, v: i32) -> Result<Self::Ok> {
+        self.serialize_i64(v as i64)
+    }
+
+    fn serialize_i64(self, v: i64) -> Result<Self::Ok> {
+        self.serialize_primitive(v)
+    }
+
+    fn serialize_u8(self, v: u8) -> Result<Self::Ok> {
+        self.serialize_u64(v as u64)
+    }
+
+    fn serialize_u16(self, v: u16) -> Result<Self::Ok> {
+        self.serialize_u64(v as u64)
+    }
+
+    fn serialize_u32(self, v: u32) -> Result<Self::Ok> {
+        self.serialize_u64(v as u64)
+    }
+
+    fn serialize_u64(self, v: u64) -> Result<Self::Ok> {
+        if v > (i64::max_value() as u64) {
+            Err(ConfigError::Message(
+                format!("value {} is greater than the max {}", v, i64::max_value())
+            ))
+        } else {
+            self.serialize_i64(v as i64)
+        }
+    }
+
+    fn serialize_f32(self, v: f32) -> Result<Self::Ok> {
+        self.serialize_f64(v as f64)
+    }
+
+    fn serialize_f64(self, v: f64) -> Result<Self::Ok> {
+        self.serialize_primitive(v)
+    }
+
+    fn serialize_char(self, v: char) -> Result<Self::Ok> {
+        self.serialize_primitive(v.to_string())
+    }
+
+    fn serialize_str(self, v: &str) -> Result<Self::Ok> {
+        self.serialize_primitive(v.to_string())
+    }
+
+    fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok> {
+        use serde::ser::SerializeSeq;
+        let mut seq = self.serialize_seq(Some(v.len()))?;
+        for byte in v {
+            seq.serialize_element(byte)?;
+        }
+        seq.end()
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok> {
+        self.serialize_unit()
+    }
+
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok>
+        where T: ?Sized + ser::Serialize
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok> {
+        self.serialize_primitive(Value::from(ValueKind::Nil))
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok> {
+        self.serialize_unit()
+    }
+
+    fn serialize_unit_variant(self, _name: &'static str, _variant_index: u32, variant: &'static str)
+        -> Result<Self::Ok>
+    {
+        self.serialize_str(&variant.to_lowercase())
+    }
+
+    fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> Result<Self::Ok>
+        where T: ?Sized + ser::Serialize
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T>(self, _name: &'static str, _variant_index: u32, variant: &'static str, value: &T)
+        -> Result<Self::Ok>
+        where T: ?Sized + ser::Serialize
+    {
+        self.push_key(&variant.to_lowercase());
+        value.serialize(&mut *self)?;
+        self.pop_key();
+        Ok(())
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
+        Ok(self)
+    }
+
+    fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple> {
+        self.serialize_seq(Some(len))
+    }
+
+    fn serialize_tuple_struct(self, _name: &'static str, len: usize)
+        -> Result<Self::SerializeTupleStruct>
+    {
+        self.serialize_seq(Some(len))
+    }
+
+    fn serialize_tuple_variant(self, name: &'static str, _variant_index: u32, variant: &'static str, _len: usize)
+        -> Result<Self::SerializeTupleVariant>
+    {
+        self.push_key(&variant.to_lowercase());
+        Ok(self)
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
+        Ok(self)
+    }
+
+    fn serialize_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
+        self.serialize_map(Some(len))
+    }
+
+    fn serialize_struct_variant(self, _name: &'static str, _variant_index: u32, variant: &'static str, len: usize)
+        -> Result<Self::SerializeStructVariant>
+    {
+        self.push_key(&variant.to_lowercase());
+        Ok(self)
+    }
+}
+
+impl<'a> ser::SerializeSeq for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+
+    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        self.inc_last_key_index()?;
+        value.serialize(&mut **self)?;
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        Ok(())
+    }
+}
+
+impl<'a> ser::SerializeTuple for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+
+    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        self.inc_last_key_index()?;
+        value.serialize(&mut **self)?;
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        Ok(())
+    }
+}
+
+impl<'a> ser::SerializeTupleStruct for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        self.inc_last_key_index()?;
+        value.serialize(&mut **self)?;
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        Ok(())
+    }
+}
+
+impl<'a> ser::SerializeTupleVariant for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        self.inc_last_key_index()?;
+        value.serialize(&mut **self)?;
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        self.pop_key();
+        Ok(())
+    }
+}
+
+impl<'a> ser::SerializeMap for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+
+    fn serialize_key<T>(&mut self, key: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        let key_serializer = StringKeySerializer;
+        let key = key.serialize(key_serializer)?;
+        self.push_key(&key);
+        Ok(())
+    }
+
+    fn serialize_value<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        value.serialize(&mut **self)?;
+        self.pop_key();
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        Ok(())
+    }
+}
+
+impl<'a> ser::SerializeStruct for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        self.push_key(key);
+        value.serialize(&mut **self)?;
+        self.pop_key();
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        Ok(())
+    }
+}
+
+impl<'a> ser::SerializeStructVariant for &'a mut ConfigSerializer {
+    type Ok = ();
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        self.push_key(key);
+        value.serialize(&mut **self)?;
+        self.pop_key();
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        self.pop_key();
+        Ok(())
+    }
+}
+
+pub struct StringKeySerializer;
+
+impl ser::Serializer for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+    type SerializeSeq = Self;
+    type SerializeTuple = Self;
+    type SerializeTupleStruct = Self;
+    type SerializeTupleVariant = Self;
+    type SerializeMap = Self;
+    type SerializeStruct = Self;
+    type SerializeStructVariant = Self;
+
+    fn serialize_bool(self, v: bool) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_i8(self, v: i8) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_i16(self, v: i16) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_i32(self, v: i32) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_i64(self, v: i64) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_u8(self, v: u8) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_u16(self, v: u16) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_u32(self, v: u32) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_u64(self, v: u64) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_f32(self, v: f32) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_f64(self, v: f64) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_char(self, v: char) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_str(self, v: &str) -> Result<Self::Ok> {
+        Ok(v.to_string())
+    }
+
+    fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok> {
+        Ok(String::from_utf8_lossy(v).to_string())
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok> {
+        self.serialize_unit()
+    }
+
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok>
+        where T: ?Sized + ser::Serialize
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok> {
+        Ok(String::new())
+    }
+
+    fn serialize_unit_struct(self, _name: &str) -> Result<Self::Ok> {
+        self.serialize_unit()
+    }
+
+    fn serialize_unit_variant(self, _name: &str, _variant_index: u32, variant: &str) -> Result<Self::Ok> {
+        Ok(variant.to_lowercase())
+    }
+
+    fn serialize_newtype_struct<T>(self, _name: &str, value: &T) -> Result<Self::Ok>
+        where T: ?Sized + ser::Serialize
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T>(self, _name: &str, _variant_index: u32, _variant: &str, value: &T)
+        -> Result<Self::Ok>
+        where T: ?Sized + ser::Serialize
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
+        Err(ConfigError::Message("seq can't serialize to string key".to_string()))
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple> {
+        Err(ConfigError::Message("tuple can't serialize to string key".to_string()))
+    }
+
+    fn serialize_tuple_struct(self, name: &str, _len: usize) -> Result<Self::SerializeTupleStruct> {
+        Err(ConfigError::Message(format!("tuple struct {} can't serialize to string key", name)))
+    }
+
+    fn serialize_tuple_variant(self, name: &str, _variant_index: u32, variant: &str, _len: usize)
+        -> Result<Self::SerializeTupleVariant>
+    {
+        Err(ConfigError::Message(format!("tuple variant {}::{} can't serialize to string key", name, variant)))
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
+        Err(ConfigError::Message("map can't serialize to string key".to_string()))
+    }
+
+    fn serialize_struct(self, name: &str, _len: usize) -> Result<Self::SerializeStruct> {
+        Err(ConfigError::Message(format!("struct {} can't serialize to string key", name)))
+    }
+
+    fn serialize_struct_variant(self, name: &str, _variant_index: u32, variant: &str, _len: usize)
+        -> Result<Self::SerializeStructVariant>
+    {
+        Err(ConfigError::Message(format!("struct variant {}::{} can't serialize to string key", name, variant)))
+    }
+}
+
+
+impl ser::SerializeSeq for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+
+    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        unreachable!()
+    }
+}
+
+impl ser::SerializeTuple for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+
+    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        unreachable!()
+    }
+}
+
+impl ser::SerializeTupleStruct for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        unreachable!()
+    }
+}
+
+impl ser::SerializeTupleVariant for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        unreachable!()
+    }
+}
+
+impl ser::SerializeMap for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+
+    fn serialize_key<T>(&mut self, key: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn serialize_value<T>(&mut self, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        unreachable!()
+    }
+}
+
+impl ser::SerializeStruct for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        unreachable!()
+    }
+}
+
+impl ser::SerializeStructVariant for StringKeySerializer {
+    type Ok = String;
+    type Error = ConfigError;
+
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+        where T: ?Sized + ser::Serialize
+    {
+        unreachable!()
+    }
+
+    fn end(self) -> Result<Self::Ok> {
+        unreachable!()
+    }
+}