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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291
// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//! Initializers for ICU data files.
//!
//! Use the library by instantiating a `Loader` and keeping a reference to it for as long as you
//! need access to timezone data. You can do this in your program as many times as needed, and the
//! loader will make sure that the data is loaded before it is first used, and that it is unloaded
//! once no more loaders are live.
//!
//! It is also possible to clone a loader in case you need to pass it along to ensure that timezone
//! data is available.
//!
//! Example use:
//!
//! ```
//! fn basic() {
//! let _loader = Loader::new().expect("loader is constructed with success");
//! let _loader2 = Loader::new().expect("second initialization is a no-operation");
//! let _loader3 = _loader2.clone(); // It is OK to clone a loader and keep it around.
//! }
//! ```
use std::path::PathBuf;
use anyhow::{format_err, Context};
use lazy_static::lazy_static;
use std::borrow::Cow;
use std::sync::{Arc, Mutex, Weak};
use std::{env, fs, io};
use thiserror::Error;
use {
fuchsia_zircon as zx, rust_icu_common as icu, rust_icu_ucal as ucal, rust_icu_udata as udata,
};
lazy_static! {
// The storage for the loaded ICU data. At most one may be loaded at any given time.
static ref REFCOUNT: Mutex<Weak<PathBuf>> = Mutex::new(Weak::new());
}
// The default location at which to find the ICU data.
// The icudtl.dat is deliberately omitted to conform to the loading
// rules described at:
// https://unicode-org.github.io/icu/userguide/icu_data/#how-data-loading-works
const ICU_DATA_PATH_DEFAULT: &str = "/pkg/data";
/// Minimum expected length of a time zone revision ID (e.g. "2019c").
const MIN_TZ_REVISION_ID_LENGTH: usize = 5;
/// Maximum expected length of a time zone revision ID.
const MAX_TZ_REVISION_ID_LENGTH: usize = 15;
/// Error type returned by `icu_udata`. The individual enum values encode
/// classes of possible errors returned.
#[derive(Error, Debug)]
pub enum Error {
#[error("[icu_data]: {}", _0)]
Fail(anyhow::Error),
/// The operation failed due to an underlying Zircon error.
#[error("[icu_data]: generic error: {}, details: {:?}", _0, _1)]
Status(zx::Status, Option<Cow<'static, str>>),
/// The operation failed due to an IO error.
#[error("[icu_data]: IO error: {}", _0)]
IO(io::Error),
/// The operation failed due to an ICU library error.
#[error("[icu_data]: ICU error: {}", _0)]
ICU(icu::Error),
}
impl From<zx::Status> for Error {
fn from(status: zx::Status) -> Self {
Error::Status(status, None)
}
}
impl From<io::Error> for Error {
fn from(err: io::Error) -> Self {
Error::IO(err)
}
}
impl From<anyhow::Error> for Error {
fn from(err: anyhow::Error) -> Self {
Error::Fail(err)
}
}
impl From<icu::Error> for Error {
fn from(err: icu::Error) -> Self {
Error::ICU(err)
}
}
/// Manages the lifecycle of the loaded ICU data.
///
/// `Loader` can be created using `Loader::new` and can be cloned. For as long as any Loader
/// remains in scope, the ICU data will not be unloaded.
#[derive(Debug, Clone)]
pub struct Loader {
// The reference here holds the ICU data in memory. It should be held live
// until the end of the program.
_refs: Arc<PathBuf>,
}
// Loader is OK to be sent to threads.
unsafe impl Sync for Loader {}
impl Loader {
/// Initializes the ICU dynamic timezone data, based on the default resource directory.
///
/// The caller should create a `Loader` very early on in the lifetime of the program, and keep
/// instances of `Loader` alive until the ICU data is needed. You can make as many `Loader`
/// objects as you need. The data will be unloaded only after the last of them leaves scope.
pub fn new() -> Result<Self, Error> {
Self::new_with_optional_tz_resources(None, None)
}
/// Initializes ICU data, loading time zone resources from the supplied `path`.
///
/// See documentation for `new` for calling constraints.
pub fn new_with_tz_resource_path(tzdata_dir_path: &str) -> Result<Self, Error> {
Self::new_with_optional_tz_resources(Some(tzdata_dir_path), None)
}
/// Initializes ICU data, loading time zone resources from the supplied `path` and validating
/// the time zone revision ID against the ID contained in the file at `revision_file_path`.
///
/// See documentation for `new` for calling constraints.
pub fn new_with_tz_resources_and_validation(
tzdata_dir_path: &str,
tz_revision_file_path: &str,
) -> Result<Self, Error> {
Self::new_with_optional_tz_resources(Some(tzdata_dir_path), Some(tz_revision_file_path))
}
// Ensures that all calls to create a `Loader` go through the same code path.
fn new_with_optional_tz_resources(
tzdata_dir_path: Option<&str>,
tz_revision_file_path: Option<&str>,
) -> Result<Self, Error> {
// The lock contention should not be an issue. Only a few calls (single digits) to this
// function are expected. So we take a write lock immmediately.
let mut l = REFCOUNT.lock().expect("refcount lock acquired");
match l.upgrade() {
Some(_refs) => Ok(Loader { _refs }),
None => {
// Load up the TZ files directory.
if let Some(p) = tzdata_dir_path {
let for_path = fs::File::open(p)
.map_err(|e| Error::Fail(format_err!("io error: {}", e)))
.with_context(|| format!("error while opening: {:?}", &tzdata_dir_path))?;
let meta = for_path
.metadata()
.with_context(|| format!("while getting metadata for: {:?}", &p))?;
if !meta.is_dir() {
return Err(Error::Fail(format_err!("not a directory: {}", p)));
}
// This is the default API used to configure the ICU library, so we are
// just using it here. Even though it is not a preferred way to configure
// Fuchsia programs.
// Further, we want to load the same ICU data for all programs that need this
// file.
env::set_var("ICU_TIMEZONE_FILES_DIR", p);
}
// Read ICU data file from the filesystem. The ICU library should
// take care to load only the needed parts, since the entire common
// data file is fairly large.
let path = PathBuf::from(ICU_DATA_PATH_DEFAULT);
udata::set_data_directory(&path);
let _refs = Arc::new(path);
Self::validate_revision(tz_revision_file_path)?;
(*l) = Arc::downgrade(&_refs);
Ok(Loader { _refs })
}
}
}
fn validate_revision(tz_revision_file_path: Option<&str>) -> Result<(), Error> {
match tz_revision_file_path {
None => Ok(()),
Some(tz_revision_file_path) => {
let expected_revision_id = std::fs::read_to_string(tz_revision_file_path)
.with_context(|| {
format!("could not read file: {:?}", &tz_revision_file_path)
})?;
if !(MIN_TZ_REVISION_ID_LENGTH..=MAX_TZ_REVISION_ID_LENGTH)
.contains(&expected_revision_id.len())
{
return Err(Error::Status(
zx::Status::IO_DATA_INTEGRITY,
Some(
format!(
"invalid revision ID in {}: {}",
tz_revision_file_path, expected_revision_id
)
.into(),
),
));
}
let actual_revision_id = ucal::get_tz_data_version().with_context(|| {
format!("while getting data version from: {:?}", &tz_revision_file_path)
})?;
if expected_revision_id != actual_revision_id {
return Err(Error::Status(
zx::Status::IO_DATA_INTEGRITY,
Some(
format!(
"expected revision ID {} but got {}",
expected_revision_id, actual_revision_id
)
.into(),
),
));
}
Ok(())
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use assert_matches::assert_matches;
use rust_icu_uenum as uenum;
// [START loader_example]
#[test]
fn initialization() {
let _loader = Loader::new().expect("loader is constructed with success");
let _loader2 = Loader::new().expect("loader is just fine with a second initialization");
let tz: String = uenum::open_time_zones().unwrap().take(1).map(|e| e.unwrap()).collect();
assert_eq!(tz, "ACT");
// The library will be cleaned up after the last of the loaders goes out of scope.
}
#[test]
fn you_can_also_clone_loaders() {
let _loader = Loader::new().expect("loader is constructed with success");
let _loader2 = Loader::new().expect("loader is just fine with a second initialization");
let _loader3 = _loader2.clone();
let tz: String = uenum::open_time_zones().unwrap().take(1).map(|e| e.unwrap()).collect();
assert_eq!(tz, "ACT");
}
#[test]
fn two_initializations_in_a_row() {
{
let _loader = Loader::new().expect("loader is constructed with success");
let tz: String =
uenum::open_time_zones().unwrap().take(1).map(|e| e.unwrap()).collect();
assert_eq!(tz, "ACT");
}
{
let _loader2 = Loader::new().expect("loader is just fine with a second initialization");
let tz: String =
uenum::open_time_zones().unwrap().take(1).map(|e| e.unwrap()).collect();
assert_eq!(tz, "ACT");
}
}
// [END loader_example]
#[test]
fn test_tz_res_loading_without_validation() -> Result<(), Error> {
let _loader = Loader::new().expect("loader is constructed with success");
let tz: String = uenum::open_time_zones()?.take(1).map(|e| e.unwrap()).collect();
assert_eq!(tz, "ACT");
Ok(())
}
#[test]
fn test_tz_res_loading_with_validation_valid() -> Result<(), Error> {
let _loader = Loader::new_with_tz_resources_and_validation(
"/pkg/data/tzdata/icu/44/le",
"/pkg/data/tzdata/revision.txt",
)
.expect("loader is constructed successfully");
let tz: String = uenum::open_time_zones()?.take(1).map(|e| e.unwrap()).collect();
assert_eq!(tz, "ACT");
Ok(())
}
#[test]
fn test_tz_res_loading_with_validation_invalid() -> Result<(), Error> {
let result = Loader::new_with_tz_resources_and_validation(
"/pkg/data/tzdata/icu/44/le",
"/pkg/data/test_inconsistent_revision.txt",
);
let err = result.unwrap_err();
assert_matches!(err, Error::Status(zx::Status::IO_DATA_INTEGRITY, Some(_)));
Ok(())
}
}