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
use std::io::Cursor; use byteorder::{LittleEndian, ReadBytesExt}; use std::rc::Rc; use errors::*; use model::StringTable; use encoding::codec::{utf_16, utf_8}; use model::owned::{StringTableBuf, Encoding as EncodingType}; use std::cell::RefCell; use std::collections::HashMap; use std::collections::hash_map::Entry::{Occupied, Vacant}; pub struct StringTableWrapper<'a> { raw_data: &'a [u8], } impl<'a> StringTableWrapper<'a> { pub fn new(slice: &'a [u8]) -> Self { StringTableWrapper { raw_data: slice } } pub fn get_flags(&self) -> u32 { let mut cursor = Cursor::new(self.raw_data); cursor.set_position(16); cursor.read_u32::<LittleEndian>().unwrap_or(0) } pub fn to_buffer(&self) -> Result<StringTableBuf> { let mut owned = StringTableBuf::default(); if !self.is_utf8() { owned.set_encoding(EncodingType::Utf16); } for i in 0..self.get_strings_len() { let string = &*self.get_string(i)?; owned.add_string(string.clone()); } Ok(owned) } fn get_string_position(&self, idx: u32) -> Result<u64> { let mut cursor = Cursor::new(self.raw_data); cursor.set_position(20); let str_offset = cursor.read_u32::<LittleEndian>()?; cursor.set_position(28); let mut position = str_offset; let mut max_offset = 0; for _ in 0..(idx + 1) { let current_offset = cursor.read_u32::<LittleEndian>()?; position = str_offset.wrapping_add(current_offset); if current_offset > max_offset { max_offset = current_offset } } Ok(position as u64) } fn parse_string(&self, offset: u32) -> Result<String> { let mut cursor = Cursor::new(self.raw_data); cursor.set_position(offset as u64); if self.is_utf8() { let mut ini_offset = offset; let v = cursor.read_u8()? as u32; if v == 0x80 { ini_offset += 2; cursor.read_u8()?; } else { ini_offset += 1; } let v = cursor.read_u8()? as u32; if v == 0x80 { ini_offset += 2; cursor.read_u8()?; } else { ini_offset += 1; } let mut length = 0; loop { let v = cursor.read_u8()?; if v != 0 { length += 1; } else { break; } } let a = ini_offset; let b = ini_offset + length; if a > self.raw_data.len() as u32 || b > self.raw_data.len() as u32 || a > b { return Err("Sub-slice out of raw_data range".into()); } let subslice: &[u8] = &self.raw_data[a as usize..b as usize]; let mut decoder = utf_8::UTF8Decoder::new(); let mut o = String::new(); decoder.raw_feed(subslice, &mut o); let decode_error = decoder.raw_finish(&mut o); match decode_error { None => Ok(o), Some(_) => Err("Error decoding UTF8 string".into()), } } else { let size1 = cursor.read_u8()? as u32; let size2 = cursor.read_u8()? as u32; let val = ((size2 & 0xFF) << 8) | size1 & 0xFF; let a = offset + 2; let b = offset + 2 + (val * 2); if a > self.raw_data.len() as u32 || b > self.raw_data.len() as u32 || a > b { return Err("Sub-slice out of raw_data range".into()); } let subslice: &[u8] = &self.raw_data[a as usize..b as usize]; let mut decoder = utf_16::UTF16Decoder::<utf_16::Little>::new(); let mut o = String::new(); decoder.raw_feed(subslice, &mut o); let decode_error = decoder.raw_finish(&mut o); match decode_error { None => Ok(o), Some(_) => Err("Error decoding UTF16 string".into()), } } } fn is_utf8(&self) -> bool { (self.get_flags() & 0x00000100) == 0x00000100 } } impl<'a> StringTable for StringTableWrapper<'a> { fn get_strings_len(&self) -> u32 { let mut cursor = Cursor::new(self.raw_data); cursor.set_position(8); cursor.read_u32::<LittleEndian>().unwrap_or(0) } fn get_styles_len(&self) -> u32 { let mut cursor = Cursor::new(self.raw_data); cursor.set_position(12); cursor.read_u32::<LittleEndian>().unwrap_or(0) } fn get_string(&self, idx: u32) -> Result<Rc<String>> { if idx > self.get_strings_len() { return Err("Index out of bounds".into()); } let string = self.get_string_position(idx).and_then(|position| { self.parse_string(position as u32) })?; Ok(Rc::new(string)) } } pub struct StringTableCache<S: StringTable> { inner: S, cache: RefCell<HashMap<u32, Rc<String>>>, } impl<S: StringTable> StringTableCache<S> { pub fn new(inner: S) -> Self { StringTableCache { inner: inner, cache: RefCell::new(HashMap::new()), } } } impl<S: StringTable> StringTable for StringTableCache<S> { fn get_strings_len(&self) -> u32 { self.inner.get_strings_len() } fn get_styles_len(&self) -> u32 { self.inner.get_styles_len() } fn get_string(&self, idx: u32) -> Result<Rc<String>> { let mut cache = self.cache.borrow_mut(); let entry = cache.entry(idx); match entry { Vacant(entry) => { let string_ref = self.inner.get_string(idx)?; entry.insert(string_ref.clone()); Ok(string_ref) } Occupied(entry) => Ok(entry.get().clone()), } } }