1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218
//! fastnbt aims for fast parsing of NBT data from *Minecraft: Java Edition*. //! This format is used by the game to store various things, such as the world //! data and player inventories. //! //! * For documentation and examples of serde deserialization, see [`de`]. //! * For a `serde_json`-like `Value` type see [`Value`]. //! * For NBT array types see [`ByteArray`], [`IntArray`], and [`LongArray`]. //! * For 'zero-copy' NBT array types see [`borrow`]. //! //! Both this and related crates are under one [fastnbt Github //! repository](https://github.com/owengage/fastnbt) //! //! ```toml //! [dependencies] //! fastnbt = "1" //! ``` //! //! # Byte, Int and Long array types //! //! To support `Value` capturing all NBT tag information, this deserializer //! produces the `ByteArray`, `IntArray` and `LongArray` NBT data as a map //! containing the original NBT tag and the data. In order to capture these //! types in your own structs, use the appropriate type in this crate: //! [`ByteArray`], [`IntArray`] and [`LongArray`]. These types have an `iter()` //! method similar to [`Vec`][`std::vec::Vec`]. //! //! # Quick example //! //! This example demonstrates printing out a players inventory and ender chest //! contents from the [player dat //! files](https://minecraft.gamepedia.com/Player.dat_format) found in worlds. //! //! Here we //! * use serde's renaming attributes to have rustfmt conformant field names, //! * use lifetimes to save on some string allocations, and //! * use the `Value` type to deserialize a field we don't know the exact //! structure of. //! //!```no_run //! use fastnbt::error::Result; //! use fastnbt::{de::from_bytes, Value}; //! use flate2::read::GzDecoder; //! use serde::Deserialize; //! use std::io::Read; //! //! #[derive(Deserialize, Debug)] //! #[serde(rename_all = "PascalCase")] //! struct PlayerDat<'a> { //! data_version: i32, //! //! #[serde(borrow)] //! inventory: Vec<InventorySlot<'a>>, //! ender_items: Vec<InventorySlot<'a>>, //! } //! //! #[derive(Deserialize, Debug)] //! struct InventorySlot<'a> { //! id: &'a str, // We avoid allocating a string here. //! tag: Option<Value>, // Also get the less structured properties of the object. //! //! // We need to rename fields a lot. //! #[serde(rename = "Count")] //! count: i8, //! } //! //! fn main() { //! let args: Vec<_> = std::env::args().skip(1).collect(); //! let file = std::fs::File::open(args[0].clone()).unwrap(); //! //! // Player dat files are compressed with GZip. //! let mut decoder = GzDecoder::new(file); //! let mut data = vec![]; //! decoder.read_to_end(&mut data).unwrap(); //! //! let player: Result<PlayerDat> = from_bytes(data.as_slice()); //! //! println!("{:#?}", player); //! } //! ``` //! //! # `Read` based parser //! //! A lower level parser also exists in the `stream` module that only requires //! the `Read` trait on the input. This parser however doesn't support //! deserializing to Rust objects directly. //! use serde::Deserialize; pub mod borrow; pub mod de; pub mod error; pub mod stream; mod arrays; mod value; pub use arrays::*; pub use value::*; pub(crate) mod de_arrays; #[cfg(test)] mod test; use std::convert::{TryFrom, TryInto}; /// An NBT tag. This does not carry the value or the name of the data. #[derive(Deserialize, Debug, PartialEq, Clone, Copy)] #[repr(u8)] pub enum Tag { /// Represents the end of a Compound object. End = 0, /// Equivalent to i8. Byte = 1, /// Equivalent to i16. Short = 2, /// Equivalent to i32. Int = 3, /// Equivalent to i64 Long = 4, /// Equivalent to f32. Float = 5, /// Equivalent to f64. Double = 6, /// Represents as array of Byte (i8). ByteArray = 7, /// Represents a Unicode string. String = 8, /// Represents a list of other objects, elements are not required to be the same type. List = 9, /// Represents a struct-like structure. Compound = 10, /// Represents as array of Int (i32). IntArray = 11, /// Represents as array of Long (i64). LongArray = 12, } pub(crate) const BYTE_ARRAY_TAG: u8 = 7; pub(crate) const INT_ARRAY_TAG: u8 = 11; pub(crate) const LONG_ARRAY_TAG: u8 = 12; // Crates exist to generate this code for us, but would add to our compile // times, so we instead right it out manually, the tags will very rarely change // so isn't a massive burden, but saves a significant amount of compile time. impl TryFrom<u8> for Tag { type Error = (); fn try_from(value: u8) -> Result<Self, ()> { use Tag::*; Ok(match value { 0 => End, 1 => Byte, 2 => Short, 3 => Int, 4 => Long, 5 => Float, 6 => Double, 7 => ByteArray, 8 => String, 9 => List, 10 => Compound, 11 => IntArray, 12 => LongArray, 13..=u8::MAX => return Err(()), }) } } impl From<Tag> for u8 { fn from(tag: Tag) -> Self { match tag { Tag::End => 0, Tag::Byte => 1, Tag::Short => 2, Tag::Int => 3, Tag::Long => 4, Tag::Float => 5, Tag::Double => 6, Tag::ByteArray => 7, Tag::String => 8, Tag::List => 9, Tag::Compound => 10, Tag::IntArray => 11, Tag::LongArray => 12, } } } /// Compile time NBT tag type. Useful for forcing a custom type to have a field /// that must be a given tag. Used for the Array types. #[derive(Clone, Copy, PartialEq)] pub(crate) struct CompTag<const N: u8>; impl<'de, const N: u8> Deserialize<'de> for CompTag<N> { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: serde::Deserializer<'de>, { let tag: u8 = Deserialize::deserialize(deserializer)?; if tag != N { Err(serde::de::Error::custom("unexpected array type")) } else { Ok(Self) } } } impl<const N: u8> std::fmt::Debug for CompTag<N> { fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { let tag = <u8 as TryInto<Tag>>::try_into(N); match tag { Ok(tag) => tag.fmt(f), Err(_) => write!(f, "InvalidTag({})", N), } } }