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use crate::trace::{TraceError, TraceResult};
use std::collections::VecDeque;
use std::fmt;
use std::hash::Hash;
use std::num::ParseIntError;
use std::ops::{BitAnd, BitOr, Not};
use std::str::FromStr;
use thiserror::Error;
/// Flags that can be set on a [`SpanContext`].
///
/// The current version of the specification only supports a single flag
/// [`TraceFlags::SAMPLED`].
///
/// See the W3C TraceContext specification's [trace-flags] section for more
/// details.
///
/// [trace-flags]: https://www.w3.org/TR/trace-context/#trace-flags
#[derive(Clone, Debug, Default, PartialEq, Eq, Copy, Hash)]
pub struct TraceFlags(u8);
impl TraceFlags {
/// Trace flags with the `sampled` flag set to `0`.
///
/// Spans that are not sampled will be ignored by most tracing tools.
/// See the `sampled` section of the [W3C TraceContext specification] for details.
///
/// [W3C TraceContext specification]: https://www.w3.org/TR/trace-context/#sampled-flag
pub const NOT_SAMPLED: TraceFlags = TraceFlags(0x00);
/// Trace flags with the `sampled` flag set to `1`.
///
/// Spans that are not sampled will be ignored by most tracing tools.
/// See the `sampled` section of the [W3C TraceContext specification] for details.
///
/// [W3C TraceContext specification]: https://www.w3.org/TR/trace-context/#sampled-flag
pub const SAMPLED: TraceFlags = TraceFlags(0x01);
/// Construct new trace flags
pub const fn new(flags: u8) -> Self {
TraceFlags(flags)
}
/// Returns `true` if the `sampled` flag is set
pub fn is_sampled(&self) -> bool {
(*self & TraceFlags::SAMPLED) == TraceFlags::SAMPLED
}
/// Returns copy of the current flags with the `sampled` flag set.
pub fn with_sampled(&self, sampled: bool) -> Self {
if sampled {
*self | TraceFlags::SAMPLED
} else {
*self & !TraceFlags::SAMPLED
}
}
/// Returns the flags as a `u8`
pub fn to_u8(self) -> u8 {
self.0
}
}
impl BitAnd for TraceFlags {
type Output = Self;
fn bitand(self, rhs: Self) -> Self::Output {
Self(self.0 & rhs.0)
}
}
impl BitOr for TraceFlags {
type Output = Self;
fn bitor(self, rhs: Self) -> Self::Output {
Self(self.0 | rhs.0)
}
}
impl Not for TraceFlags {
type Output = Self;
fn not(self) -> Self::Output {
Self(!self.0)
}
}
impl fmt::LowerHex for TraceFlags {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::LowerHex::fmt(&self.0, f)
}
}
/// A 16-byte value which identifies a given trace.
///
/// The id is valid if it contains at least one non-zero byte.
#[derive(Clone, PartialEq, Eq, Copy, Hash)]
pub struct TraceId(u128);
impl TraceId {
/// Invalid trace id
pub const INVALID: TraceId = TraceId(0);
/// Create a trace id from its representation as a byte array.
pub const fn from_bytes(bytes: [u8; 16]) -> Self {
TraceId(u128::from_be_bytes(bytes))
}
/// Return the representation of this trace id as a byte array.
pub const fn to_bytes(self) -> [u8; 16] {
self.0.to_be_bytes()
}
/// Converts a string in base 16 to a trace id.
///
/// # Examples
///
/// ```
/// use opentelemetry::trace::TraceId;
///
/// assert!(TraceId::from_hex("42").is_ok());
/// assert!(TraceId::from_hex("58406520a006649127e371903a2de979").is_ok());
///
/// assert!(TraceId::from_hex("not_hex").is_err());
/// ```
pub fn from_hex(hex: &str) -> Result<Self, ParseIntError> {
u128::from_str_radix(hex, 16).map(TraceId)
}
}
impl From<u128> for TraceId {
fn from(value: u128) -> Self {
TraceId(value)
}
}
impl fmt::Debug for TraceId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_fmt(format_args!("{:032x}", self.0))
}
}
impl fmt::Display for TraceId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_fmt(format_args!("{:032x}", self.0))
}
}
impl fmt::LowerHex for TraceId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::LowerHex::fmt(&self.0, f)
}
}
/// An 8-byte value which identifies a given span.
///
/// The id is valid if it contains at least one non-zero byte.
#[derive(Clone, PartialEq, Eq, Copy, Hash)]
pub struct SpanId(u64);
impl SpanId {
/// Invalid span id
pub const INVALID: SpanId = SpanId(0);
/// Create a span id from its representation as a byte array.
pub const fn from_bytes(bytes: [u8; 8]) -> Self {
SpanId(u64::from_be_bytes(bytes))
}
/// Return the representation of this span id as a byte array.
pub const fn to_bytes(self) -> [u8; 8] {
self.0.to_be_bytes()
}
/// Converts a string in base 16 to a span id.
///
/// # Examples
///
/// ```
/// use opentelemetry::trace::SpanId;
///
/// assert!(SpanId::from_hex("42").is_ok());
/// assert!(SpanId::from_hex("58406520a0066491").is_ok());
///
/// assert!(SpanId::from_hex("not_hex").is_err());
/// ```
pub fn from_hex(hex: &str) -> Result<Self, ParseIntError> {
u64::from_str_radix(hex, 16).map(SpanId)
}
}
impl From<u64> for SpanId {
fn from(value: u64) -> Self {
SpanId(value)
}
}
impl fmt::Debug for SpanId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_fmt(format_args!("{:016x}", self.0))
}
}
impl fmt::Display for SpanId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_fmt(format_args!("{:016x}", self.0))
}
}
impl fmt::LowerHex for SpanId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::LowerHex::fmt(&self.0, f)
}
}
/// TraceState carries system-specific configuration data, represented as a list
/// of key-value pairs. TraceState allows multiple tracing systems to
/// participate in the same trace.
///
/// Please review the [W3C specification] for details on this field.
///
/// [W3C specification]: https://www.w3.org/TR/trace-context/#tracestate-header
#[derive(Clone, Debug, Default, Eq, PartialEq, Hash)]
pub struct TraceState(Option<VecDeque<(String, String)>>);
impl TraceState {
/// The default `TraceState`, as a constant
pub const NONE: TraceState = TraceState(None);
/// Validates that the given `TraceState` list-member key is valid per the [W3 Spec].
///
/// [W3 Spec]: https://www.w3.org/TR/trace-context/#key
fn valid_key(key: &str) -> bool {
if key.len() > 256 {
return false;
}
let allowed_special = |b: u8| (b == b'_' || b == b'-' || b == b'*' || b == b'/');
let mut vendor_start = None;
for (i, &b) in key.as_bytes().iter().enumerate() {
if !(b.is_ascii_lowercase() || b.is_ascii_digit() || allowed_special(b) || b == b'@') {
return false;
}
if i == 0 && (!b.is_ascii_lowercase() && !b.is_ascii_digit()) {
return false;
} else if b == b'@' {
if vendor_start.is_some() || i + 14 < key.len() {
return false;
}
vendor_start = Some(i);
} else if let Some(start) = vendor_start {
if i == start + 1 && !(b.is_ascii_lowercase() || b.is_ascii_digit()) {
return false;
}
}
}
true
}
/// Validates that the given `TraceState` list-member value is valid per the [W3 Spec].
///
/// [W3 Spec]: https://www.w3.org/TR/trace-context/#value
fn valid_value(value: &str) -> bool {
if value.len() > 256 {
return false;
}
!(value.contains(',') || value.contains('='))
}
/// Creates a new `TraceState` from the given key-value collection.
///
/// # Examples
///
/// ```
/// use opentelemetry::trace::TraceState;
///
/// let kvs = vec![("foo", "bar"), ("apple", "banana")];
/// let trace_state = TraceState::from_key_value(kvs);
///
/// assert!(trace_state.is_ok());
/// assert_eq!(trace_state.unwrap().header(), String::from("foo=bar,apple=banana"))
/// ```
pub fn from_key_value<T, K, V>(trace_state: T) -> TraceResult<Self>
where
T: IntoIterator<Item = (K, V)>,
K: ToString,
V: ToString,
{
let ordered_data = trace_state
.into_iter()
.map(|(key, value)| {
let (key, value) = (key.to_string(), value.to_string());
if !TraceState::valid_key(key.as_str()) {
return Err(TraceStateError::Key(key));
}
if !TraceState::valid_value(value.as_str()) {
return Err(TraceStateError::Value(value));
}
Ok((key, value))
})
.collect::<Result<VecDeque<_>, TraceStateError>>()?;
if ordered_data.is_empty() {
Ok(TraceState(None))
} else {
Ok(TraceState(Some(ordered_data)))
}
}
/// Retrieves a value for a given key from the `TraceState` if it exists.
pub fn get(&self, key: &str) -> Option<&str> {
self.0.as_ref().and_then(|kvs| {
kvs.iter().find_map(|item| {
if item.0.as_str() == key {
Some(item.1.as_str())
} else {
None
}
})
})
}
/// Inserts the given key-value pair into the `TraceState`. If a value already exists for the
/// given key, this updates the value and updates the value's position. If the key or value are
/// invalid per the [W3 Spec] an `Err` is returned, else a new `TraceState` with the
/// updated key/value is returned.
///
/// [W3 Spec]: https://www.w3.org/TR/trace-context/#mutating-the-tracestate-field
pub fn insert<K, V>(&self, key: K, value: V) -> TraceResult<TraceState>
where
K: Into<String>,
V: Into<String>,
{
let (key, value) = (key.into(), value.into());
if !TraceState::valid_key(key.as_str()) {
return Err(TraceStateError::Key(key).into());
}
if !TraceState::valid_value(value.as_str()) {
return Err(TraceStateError::Value(value).into());
}
let mut trace_state = self.delete_from_deque(key.clone());
let kvs = trace_state.0.get_or_insert(VecDeque::with_capacity(1));
kvs.push_front((key, value));
Ok(trace_state)
}
/// Removes the given key-value pair from the `TraceState`. If the key is invalid per the
/// [W3 Spec] an `Err` is returned. Else, a new `TraceState`
/// with the removed entry is returned.
///
/// If the key is not in `TraceState`. The original `TraceState` will be cloned and returned.
///
/// [W3 Spec]: https://www.w3.org/TR/trace-context/#mutating-the-tracestate-field
pub fn delete<K: Into<String>>(&self, key: K) -> TraceResult<TraceState> {
let key = key.into();
if !TraceState::valid_key(key.as_str()) {
return Err(TraceStateError::Key(key).into());
}
Ok(self.delete_from_deque(key))
}
/// Delete key from trace state's deque. The key MUST be valid
fn delete_from_deque(&self, key: String) -> TraceState {
let mut owned = self.clone();
if let Some(kvs) = owned.0.as_mut() {
if let Some(index) = kvs.iter().position(|x| *x.0 == *key) {
kvs.remove(index);
}
}
owned
}
/// Creates a new `TraceState` header string, delimiting each key and value with a `=` and each
/// entry with a `,`.
pub fn header(&self) -> String {
self.header_delimited("=", ",")
}
/// Creates a new `TraceState` header string, with the given key/value delimiter and entry delimiter.
pub fn header_delimited(&self, entry_delimiter: &str, list_delimiter: &str) -> String {
self.0
.as_ref()
.map(|kvs| {
kvs.iter()
.map(|(key, value)| format!("{}{}{}", key, entry_delimiter, value))
.collect::<Vec<String>>()
.join(list_delimiter)
})
.unwrap_or_default()
}
}
impl FromStr for TraceState {
type Err = TraceError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let list_members: Vec<&str> = s.split_terminator(',').collect();
let mut key_value_pairs: Vec<(String, String)> = Vec::with_capacity(list_members.len());
for list_member in list_members {
match list_member.find('=') {
None => return Err(TraceStateError::List(list_member.to_string()).into()),
Some(separator_index) => {
let (key, value) = list_member.split_at(separator_index);
key_value_pairs
.push((key.to_string(), value.trim_start_matches('=').to_string()));
}
}
}
TraceState::from_key_value(key_value_pairs)
}
}
/// Error returned by `TraceState` operations.
#[derive(Error, Debug)]
#[non_exhaustive]
enum TraceStateError {
/// The key is invalid.
///
/// See <https://www.w3.org/TR/trace-context/#key> for requirement for keys.
#[error("{0} is not a valid key in TraceState, see https://www.w3.org/TR/trace-context/#key for more details")]
Key(String),
/// The value is invalid.
///
/// See <https://www.w3.org/TR/trace-context/#value> for requirement for values.
#[error("{0} is not a valid value in TraceState, see https://www.w3.org/TR/trace-context/#value for more details")]
Value(String),
/// The list is invalid.
///
/// See <https://www.w3.org/TR/trace-context/#list> for requirement for list members.
#[error("{0} is not a valid list member in TraceState, see https://www.w3.org/TR/trace-context/#list for more details")]
List(String),
}
impl From<TraceStateError> for TraceError {
fn from(err: TraceStateError) -> Self {
TraceError::Other(Box::new(err))
}
}
/// Immutable portion of a [`Span`] which can be serialized and propagated.
///
/// This representation conforms to the [W3C TraceContext specification].
///
/// Spans that do not have the `sampled` flag set in their [`TraceFlags`] will
/// be ignored by most tracing tools.
///
/// [`Span`]: crate::trace::Span
/// [W3C TraceContext specification]: https://www.w3.org/TR/trace-context
#[derive(Clone, Debug, PartialEq, Hash, Eq)]
pub struct SpanContext {
trace_id: TraceId,
span_id: SpanId,
trace_flags: TraceFlags,
is_remote: bool,
trace_state: TraceState,
}
impl SpanContext {
/// An invalid span context
pub const NONE: SpanContext = SpanContext {
trace_id: TraceId::INVALID,
span_id: SpanId::INVALID,
trace_flags: TraceFlags::NOT_SAMPLED,
is_remote: false,
trace_state: TraceState::NONE,
};
/// Create an invalid empty span context
pub fn empty_context() -> Self {
SpanContext::NONE
}
/// Construct a new `SpanContext`
pub fn new(
trace_id: TraceId,
span_id: SpanId,
trace_flags: TraceFlags,
is_remote: bool,
trace_state: TraceState,
) -> Self {
SpanContext {
trace_id,
span_id,
trace_flags,
is_remote,
trace_state,
}
}
/// The [`TraceId`] for this span context.
pub fn trace_id(&self) -> TraceId {
self.trace_id
}
/// The [`SpanId`] for this span context.
pub fn span_id(&self) -> SpanId {
self.span_id
}
/// Returns details about the trace.
///
/// Unlike `TraceState` values, these are present in all traces. The current
/// version of the specification only supports a single flag [`TraceFlags::SAMPLED`].
pub fn trace_flags(&self) -> TraceFlags {
self.trace_flags
}
/// Returns `true` if the span context has a valid (non-zero) `trace_id` and a
/// valid (non-zero) `span_id`.
pub fn is_valid(&self) -> bool {
self.trace_id != TraceId::INVALID && self.span_id != SpanId::INVALID
}
/// Returns `true` if the span context was propagated from a remote parent.
pub fn is_remote(&self) -> bool {
self.is_remote
}
/// Returns `true` if the `sampled` trace flag is set.
///
/// Spans that are not sampled will be ignored by most tracing tools.
pub fn is_sampled(&self) -> bool {
self.trace_flags.is_sampled()
}
/// A reference to the span context's [`TraceState`].
pub fn trace_state(&self) -> &TraceState {
&self.trace_state
}
}
#[cfg(test)]
mod tests {
use super::*;
#[rustfmt::skip]
fn trace_id_test_data() -> Vec<(TraceId, &'static str, [u8; 16])> {
vec![
(TraceId(0), "00000000000000000000000000000000", [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]),
(TraceId(42), "0000000000000000000000000000002a", [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42]),
(TraceId(126642714606581564793456114182061442190), "5f467fe7bf42676c05e20ba4a90e448e", [95, 70, 127, 231, 191, 66, 103, 108, 5, 226, 11, 164, 169, 14, 68, 142])
]
}
#[rustfmt::skip]
fn span_id_test_data() -> Vec<(SpanId, &'static str, [u8; 8])> {
vec![
(SpanId(0), "0000000000000000", [0, 0, 0, 0, 0, 0, 0, 0]),
(SpanId(42), "000000000000002a", [0, 0, 0, 0, 0, 0, 0, 42]),
(SpanId(5508496025762705295), "4c721bf33e3caf8f", [76, 114, 27, 243, 62, 60, 175, 143])
]
}
#[rustfmt::skip]
fn trace_state_test_data() -> Vec<(TraceState, &'static str, &'static str)> {
vec![
(TraceState::from_key_value(vec![("foo", "bar")]).unwrap(), "foo=bar", "foo"),
(TraceState::from_key_value(vec![("foo", ""), ("apple", "banana")]).unwrap(), "foo=,apple=banana", "apple"),
(TraceState::from_key_value(vec![("foo", "bar"), ("apple", "banana")]).unwrap(), "foo=bar,apple=banana", "apple"),
]
}
#[test]
fn test_trace_id() {
for test_case in trace_id_test_data() {
assert_eq!(format!("{}", test_case.0), test_case.1);
assert_eq!(format!("{:032x}", test_case.0), test_case.1);
assert_eq!(test_case.0.to_bytes(), test_case.2);
assert_eq!(test_case.0, TraceId::from_hex(test_case.1).unwrap());
assert_eq!(test_case.0, TraceId::from_bytes(test_case.2));
}
}
#[test]
fn test_span_id() {
for test_case in span_id_test_data() {
assert_eq!(format!("{}", test_case.0), test_case.1);
assert_eq!(format!("{:016x}", test_case.0), test_case.1);
assert_eq!(test_case.0.to_bytes(), test_case.2);
assert_eq!(test_case.0, SpanId::from_hex(test_case.1).unwrap());
assert_eq!(test_case.0, SpanId::from_bytes(test_case.2));
}
}
#[test]
fn test_trace_state() {
for test_case in trace_state_test_data() {
assert_eq!(test_case.0.clone().header(), test_case.1);
let new_key = format!("{}-{}", test_case.0.get(test_case.2).unwrap(), "test");
let updated_trace_state = test_case.0.insert(test_case.2, new_key.clone());
assert!(updated_trace_state.is_ok());
let updated_trace_state = updated_trace_state.unwrap();
let updated = format!("{}={}", test_case.2, new_key);
let index = updated_trace_state.clone().header().find(&updated);
assert!(index.is_some());
assert_eq!(index.unwrap(), 0);
let deleted_trace_state = updated_trace_state.delete(test_case.2.to_string());
assert!(deleted_trace_state.is_ok());
let deleted_trace_state = deleted_trace_state.unwrap();
assert!(deleted_trace_state.get(test_case.2).is_none());
}
}
#[test]
fn test_trace_state_key() {
let test_data: Vec<(&'static str, bool)> = vec![
("123", true),
("bar", true),
("foo@bar", true),
("foo@0123456789abcdef", false),
("foo@012345678", true),
("FOO@BAR", false),
("你好", false),
];
for (key, expected) in test_data {
assert_eq!(TraceState::valid_key(key), expected, "test key: {:?}", key);
}
}
#[test]
fn test_trace_state_insert() {
let trace_state = TraceState::from_key_value(vec![("foo", "bar")]).unwrap();
let inserted_trace_state = trace_state.insert("testkey", "testvalue").unwrap();
assert!(trace_state.get("testkey").is_none()); // The original state doesn't change
assert_eq!(inserted_trace_state.get("testkey").unwrap(), "testvalue"); //
}
}