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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /third_party/rust/serde_json/src/error.rs | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | third_party/rust/serde_json/src/error.rs | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/third_party/rust/serde_json/src/error.rs b/third_party/rust/serde_json/src/error.rs new file mode 100644 index 0000000000..1875ef08b0 --- /dev/null +++ b/third_party/rust/serde_json/src/error.rs @@ -0,0 +1,445 @@ +//! When serializing or deserializing JSON goes wrong. + +use crate::io; +use alloc::boxed::Box; +use alloc::string::{String, ToString}; +use core::fmt::{self, Debug, Display}; +use core::result; +use core::str::FromStr; +use serde::{de, ser}; +#[cfg(feature = "std")] +use std::error; + +/// This type represents all possible errors that can occur when serializing or +/// deserializing JSON data. +pub struct Error { + /// This `Box` allows us to keep the size of `Error` as small as possible. A + /// larger `Error` type was substantially slower due to all the functions + /// that pass around `Result<T, Error>`. + err: Box<ErrorImpl>, +} + +/// Alias for a `Result` with the error type `serde_json::Error`. +pub type Result<T> = result::Result<T, Error>; + +impl Error { + /// One-based line number at which the error was detected. + /// + /// Characters in the first line of the input (before the first newline + /// character) are in line 1. + pub fn line(&self) -> usize { + self.err.line + } + + /// One-based column number at which the error was detected. + /// + /// The first character in the input and any characters immediately + /// following a newline character are in column 1. + /// + /// Note that errors may occur in column 0, for example if a read from an IO + /// stream fails immediately following a previously read newline character. + pub fn column(&self) -> usize { + self.err.column + } + + /// Categorizes the cause of this error. + /// + /// - `Category::Io` - failure to read or write bytes on an IO stream + /// - `Category::Syntax` - input that is not syntactically valid JSON + /// - `Category::Data` - input data that is semantically incorrect + /// - `Category::Eof` - unexpected end of the input data + pub fn classify(&self) -> Category { + match self.err.code { + ErrorCode::Message(_) => Category::Data, + ErrorCode::Io(_) => Category::Io, + ErrorCode::EofWhileParsingList + | ErrorCode::EofWhileParsingObject + | ErrorCode::EofWhileParsingString + | ErrorCode::EofWhileParsingValue => Category::Eof, + ErrorCode::ExpectedColon + | ErrorCode::ExpectedListCommaOrEnd + | ErrorCode::ExpectedObjectCommaOrEnd + | ErrorCode::ExpectedSomeIdent + | ErrorCode::ExpectedSomeValue + | ErrorCode::InvalidEscape + | ErrorCode::InvalidNumber + | ErrorCode::NumberOutOfRange + | ErrorCode::InvalidUnicodeCodePoint + | ErrorCode::ControlCharacterWhileParsingString + | ErrorCode::KeyMustBeAString + | ErrorCode::LoneLeadingSurrogateInHexEscape + | ErrorCode::TrailingComma + | ErrorCode::TrailingCharacters + | ErrorCode::UnexpectedEndOfHexEscape + | ErrorCode::RecursionLimitExceeded => Category::Syntax, + } + } + + /// Returns true if this error was caused by a failure to read or write + /// bytes on an IO stream. + pub fn is_io(&self) -> bool { + self.classify() == Category::Io + } + + /// Returns true if this error was caused by input that was not + /// syntactically valid JSON. + pub fn is_syntax(&self) -> bool { + self.classify() == Category::Syntax + } + + /// Returns true if this error was caused by input data that was + /// semantically incorrect. + /// + /// For example, JSON containing a number is semantically incorrect when the + /// type being deserialized into holds a String. + pub fn is_data(&self) -> bool { + self.classify() == Category::Data + } + + /// Returns true if this error was caused by prematurely reaching the end of + /// the input data. + /// + /// Callers that process streaming input may be interested in retrying the + /// deserialization once more data is available. + pub fn is_eof(&self) -> bool { + self.classify() == Category::Eof + } +} + +/// Categorizes the cause of a `serde_json::Error`. +#[derive(Copy, Clone, PartialEq, Eq, Debug)] +pub enum Category { + /// The error was caused by a failure to read or write bytes on an IO + /// stream. + Io, + + /// The error was caused by input that was not syntactically valid JSON. + Syntax, + + /// The error was caused by input data that was semantically incorrect. + /// + /// For example, JSON containing a number is semantically incorrect when the + /// type being deserialized into holds a String. + Data, + + /// The error was caused by prematurely reaching the end of the input data. + /// + /// Callers that process streaming input may be interested in retrying the + /// deserialization once more data is available. + Eof, +} + +#[cfg(feature = "std")] +#[allow(clippy::fallible_impl_from)] +impl From<Error> for io::Error { + /// Convert a `serde_json::Error` into an `io::Error`. + /// + /// JSON syntax and data errors are turned into `InvalidData` IO errors. + /// EOF errors are turned into `UnexpectedEof` IO errors. + /// + /// ``` + /// use std::io; + /// + /// enum MyError { + /// Io(io::Error), + /// Json(serde_json::Error), + /// } + /// + /// impl From<serde_json::Error> for MyError { + /// fn from(err: serde_json::Error) -> MyError { + /// use serde_json::error::Category; + /// match err.classify() { + /// Category::Io => { + /// MyError::Io(err.into()) + /// } + /// Category::Syntax | Category::Data | Category::Eof => { + /// MyError::Json(err) + /// } + /// } + /// } + /// } + /// ``` + fn from(j: Error) -> Self { + if let ErrorCode::Io(err) = j.err.code { + err + } else { + match j.classify() { + Category::Io => unreachable!(), + Category::Syntax | Category::Data => io::Error::new(io::ErrorKind::InvalidData, j), + Category::Eof => io::Error::new(io::ErrorKind::UnexpectedEof, j), + } + } + } +} + +struct ErrorImpl { + code: ErrorCode, + line: usize, + column: usize, +} + +pub(crate) enum ErrorCode { + /// Catchall for syntax error messages + Message(Box<str>), + + /// Some IO error occurred while serializing or deserializing. + Io(io::Error), + + /// EOF while parsing a list. + EofWhileParsingList, + + /// EOF while parsing an object. + EofWhileParsingObject, + + /// EOF while parsing a string. + EofWhileParsingString, + + /// EOF while parsing a JSON value. + EofWhileParsingValue, + + /// Expected this character to be a `':'`. + ExpectedColon, + + /// Expected this character to be either a `','` or a `']'`. + ExpectedListCommaOrEnd, + + /// Expected this character to be either a `','` or a `'}'`. + ExpectedObjectCommaOrEnd, + + /// Expected to parse either a `true`, `false`, or a `null`. + ExpectedSomeIdent, + + /// Expected this character to start a JSON value. + ExpectedSomeValue, + + /// Invalid hex escape code. + InvalidEscape, + + /// Invalid number. + InvalidNumber, + + /// Number is bigger than the maximum value of its type. + NumberOutOfRange, + + /// Invalid unicode code point. + InvalidUnicodeCodePoint, + + /// Control character found while parsing a string. + ControlCharacterWhileParsingString, + + /// Object key is not a string. + KeyMustBeAString, + + /// Lone leading surrogate in hex escape. + LoneLeadingSurrogateInHexEscape, + + /// JSON has a comma after the last value in an array or map. + TrailingComma, + + /// JSON has non-whitespace trailing characters after the value. + TrailingCharacters, + + /// Unexpected end of hex escape. + UnexpectedEndOfHexEscape, + + /// Encountered nesting of JSON maps and arrays more than 128 layers deep. + RecursionLimitExceeded, +} + +impl Error { + #[cold] + pub(crate) fn syntax(code: ErrorCode, line: usize, column: usize) -> Self { + Error { + err: Box::new(ErrorImpl { code, line, column }), + } + } + + // Not public API. Should be pub(crate). + // + // Update `eager_json` crate when this function changes. + #[doc(hidden)] + #[cold] + pub fn io(error: io::Error) -> Self { + Error { + err: Box::new(ErrorImpl { + code: ErrorCode::Io(error), + line: 0, + column: 0, + }), + } + } + + #[cold] + pub(crate) fn fix_position<F>(self, f: F) -> Self + where + F: FnOnce(ErrorCode) -> Error, + { + if self.err.line == 0 { + f(self.err.code) + } else { + self + } + } +} + +impl Display for ErrorCode { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + match self { + ErrorCode::Message(msg) => f.write_str(msg), + ErrorCode::Io(err) => Display::fmt(err, f), + ErrorCode::EofWhileParsingList => f.write_str("EOF while parsing a list"), + ErrorCode::EofWhileParsingObject => f.write_str("EOF while parsing an object"), + ErrorCode::EofWhileParsingString => f.write_str("EOF while parsing a string"), + ErrorCode::EofWhileParsingValue => f.write_str("EOF while parsing a value"), + ErrorCode::ExpectedColon => f.write_str("expected `:`"), + ErrorCode::ExpectedListCommaOrEnd => f.write_str("expected `,` or `]`"), + ErrorCode::ExpectedObjectCommaOrEnd => f.write_str("expected `,` or `}`"), + ErrorCode::ExpectedSomeIdent => f.write_str("expected ident"), + ErrorCode::ExpectedSomeValue => f.write_str("expected value"), + ErrorCode::InvalidEscape => f.write_str("invalid escape"), + ErrorCode::InvalidNumber => f.write_str("invalid number"), + ErrorCode::NumberOutOfRange => f.write_str("number out of range"), + ErrorCode::InvalidUnicodeCodePoint => f.write_str("invalid unicode code point"), + ErrorCode::ControlCharacterWhileParsingString => { + f.write_str("control character (\\u0000-\\u001F) found while parsing a string") + } + ErrorCode::KeyMustBeAString => f.write_str("key must be a string"), + ErrorCode::LoneLeadingSurrogateInHexEscape => { + f.write_str("lone leading surrogate in hex escape") + } + ErrorCode::TrailingComma => f.write_str("trailing comma"), + ErrorCode::TrailingCharacters => f.write_str("trailing characters"), + ErrorCode::UnexpectedEndOfHexEscape => f.write_str("unexpected end of hex escape"), + ErrorCode::RecursionLimitExceeded => f.write_str("recursion limit exceeded"), + } + } +} + +impl serde::de::StdError for Error { + #[cfg(feature = "std")] + fn source(&self) -> Option<&(dyn error::Error + 'static)> { + match &self.err.code { + ErrorCode::Io(err) => Some(err), + _ => None, + } + } +} + +impl Display for Error { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Display::fmt(&*self.err, f) + } +} + +impl Display for ErrorImpl { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + if self.line == 0 { + Display::fmt(&self.code, f) + } else { + write!( + f, + "{} at line {} column {}", + self.code, self.line, self.column + ) + } + } +} + +// Remove two layers of verbosity from the debug representation. Humans often +// end up seeing this representation because it is what unwrap() shows. +impl Debug for Error { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!( + f, + "Error({:?}, line: {}, column: {})", + self.err.code.to_string(), + self.err.line, + self.err.column + ) + } +} + +impl de::Error for Error { + #[cold] + fn custom<T: Display>(msg: T) -> Error { + make_error(msg.to_string()) + } + + #[cold] + fn invalid_type(unexp: de::Unexpected, exp: &dyn de::Expected) -> Self { + if let de::Unexpected::Unit = unexp { + Error::custom(format_args!("invalid type: null, expected {}", exp)) + } else { + Error::custom(format_args!("invalid type: {}, expected {}", unexp, exp)) + } + } +} + +impl ser::Error for Error { + #[cold] + fn custom<T: Display>(msg: T) -> Error { + make_error(msg.to_string()) + } +} + +// Parse our own error message that looks like "{} at line {} column {}" to work +// around erased-serde round-tripping the error through de::Error::custom. +fn make_error(mut msg: String) -> Error { + let (line, column) = parse_line_col(&mut msg).unwrap_or((0, 0)); + Error { + err: Box::new(ErrorImpl { + code: ErrorCode::Message(msg.into_boxed_str()), + line, + column, + }), + } +} + +fn parse_line_col(msg: &mut String) -> Option<(usize, usize)> { + let start_of_suffix = match msg.rfind(" at line ") { + Some(index) => index, + None => return None, + }; + + // Find start and end of line number. + let start_of_line = start_of_suffix + " at line ".len(); + let mut end_of_line = start_of_line; + while starts_with_digit(&msg[end_of_line..]) { + end_of_line += 1; + } + + if !msg[end_of_line..].starts_with(" column ") { + return None; + } + + // Find start and end of column number. + let start_of_column = end_of_line + " column ".len(); + let mut end_of_column = start_of_column; + while starts_with_digit(&msg[end_of_column..]) { + end_of_column += 1; + } + + if end_of_column < msg.len() { + return None; + } + + // Parse numbers. + let line = match usize::from_str(&msg[start_of_line..end_of_line]) { + Ok(line) => line, + Err(_) => return None, + }; + let column = match usize::from_str(&msg[start_of_column..end_of_column]) { + Ok(column) => column, + Err(_) => return None, + }; + + msg.truncate(start_of_suffix); + Some((line, column)) +} + +fn starts_with_digit(slice: &str) -> bool { + match slice.as_bytes().first() { + None => false, + Some(&byte) => byte >= b'0' && byte <= b'9', + } +} |