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use std::{
io::{self, Write},
path::Path,
time::Instant,
};
use {
grep_matcher::{Match, Matcher},
grep_searcher::{
Searcher, Sink, SinkContext, SinkContextKind, SinkFinish, SinkMatch,
},
serde_json as json,
};
use crate::{
counter::CounterWriter, jsont, stats::Stats, util::find_iter_at_in_context,
};
/// The configuration for the JSON printer.
///
/// This is manipulated by the JSONBuilder and then referenced by the actual
/// implementation. Once a printer is build, the configuration is frozen and
/// cannot changed.
#[derive(Debug, Clone)]
struct Config {
pretty: bool,
max_matches: Option<u64>,
always_begin_end: bool,
}
impl Default for Config {
fn default() -> Config {
Config { pretty: false, max_matches: None, always_begin_end: false }
}
}
/// A builder for a JSON lines printer.
///
/// The builder permits configuring how the printer behaves. The JSON printer
/// has fewer configuration options than the standard printer because it is
/// a structured format, and the printer always attempts to find the most
/// information possible.
///
/// Some configuration options, such as whether line numbers are included or
/// whether contextual lines are shown, are drawn directly from the
/// `grep_searcher::Searcher`'s configuration.
///
/// Once a `JSON` printer is built, its configuration cannot be changed.
#[derive(Clone, Debug)]
pub struct JSONBuilder {
config: Config,
}
impl JSONBuilder {
/// Return a new builder for configuring the JSON printer.
pub fn new() -> JSONBuilder {
JSONBuilder { config: Config::default() }
}
/// Create a JSON printer that writes results to the given writer.
pub fn build<W: io::Write>(&self, wtr: W) -> JSON<W> {
JSON {
config: self.config.clone(),
wtr: CounterWriter::new(wtr),
matches: vec![],
}
}
/// Print JSON in a pretty printed format.
///
/// Enabling this will no longer produce a "JSON lines" format, in that
/// each JSON object printed may span multiple lines.
///
/// This is disabled by default.
pub fn pretty(&mut self, yes: bool) -> &mut JSONBuilder {
self.config.pretty = yes;
self
}
/// Set the maximum amount of matches that are printed.
///
/// If multi line search is enabled and a match spans multiple lines, then
/// that match is counted exactly once for the purposes of enforcing this
/// limit, regardless of how many lines it spans.
pub fn max_matches(&mut self, limit: Option<u64>) -> &mut JSONBuilder {
self.config.max_matches = limit;
self
}
/// When enabled, the `begin` and `end` messages are always emitted, even
/// when no match is found.
///
/// When disabled, the `begin` and `end` messages are only shown if there
/// is at least one `match` or `context` message.
///
/// This is disabled by default.
pub fn always_begin_end(&mut self, yes: bool) -> &mut JSONBuilder {
self.config.always_begin_end = yes;
self
}
}
/// The JSON printer, which emits results in a JSON lines format.
///
/// This type is generic over `W`, which represents any implementation of
/// the standard library `io::Write` trait.
///
/// # Format
///
/// This section describes the JSON format used by this printer.
///
/// To skip the rigamarole, take a look at the
/// [example](#example)
/// at the end.
///
/// ## Overview
///
/// The format of this printer is the [JSON Lines](https://jsonlines.org/)
/// format. Specifically, this printer emits a sequence of messages, where
/// each message is encoded as a single JSON value on a single line. There are
/// four different types of messages (and this number may expand over time):
///
/// * **begin** - A message that indicates a file is being searched.
/// * **end** - A message the indicates a file is done being searched. This
/// message also include summary statistics about the search.
/// * **match** - A message that indicates a match was found. This includes
/// the text and offsets of the match.
/// * **context** - A message that indicates a contextual line was found.
/// This includes the text of the line, along with any match information if
/// the search was inverted.
///
/// Every message is encoded in the same envelope format, which includes a tag
/// indicating the message type along with an object for the payload:
///
/// ```json
/// {
/// "type": "{begin|end|match|context}",
/// "data": { ... }
/// }
/// ```
///
/// The message itself is encoded in the envelope's `data` key.
///
/// ## Text encoding
///
/// Before describing each message format, we first must briefly discuss text
/// encoding, since it factors into every type of message. In particular, JSON
/// may only be encoded in UTF-8, UTF-16 or UTF-32. For the purposes of this
/// printer, we need only worry about UTF-8. The problem here is that searching
/// is not limited to UTF-8 exclusively, which in turn implies that matches
/// may be reported that contain invalid UTF-8. Moreover, this printer may
/// also print file paths, and the encoding of file paths is itself not
/// guaranteed to be valid UTF-8. Therefore, this printer must deal with the
/// presence of invalid UTF-8 somehow. The printer could silently ignore such
/// things completely, or even lossily transcode invalid UTF-8 to valid UTF-8
/// by replacing all invalid sequences with the Unicode replacement character.
/// However, this would prevent consumers of this format from accessing the
/// original data in a non-lossy way.
///
/// Therefore, this printer will emit valid UTF-8 encoded bytes as normal
/// JSON strings and otherwise base64 encode data that isn't valid UTF-8. To
/// communicate whether this process occurs or not, strings are keyed by the
/// name `text` where as arbitrary bytes are keyed by `bytes`.
///
/// For example, when a path is included in a message, it is formatted like so,
/// if and only if the path is valid UTF-8:
///
/// ```json
/// {
/// "path": {
/// "text": "/home/ubuntu/lib.rs"
/// }
/// }
/// ```
///
/// If instead our path was `/home/ubuntu/lib\xFF.rs`, where the `\xFF` byte
/// makes it invalid UTF-8, the path would instead be encoded like so:
///
/// ```json
/// {
/// "path": {
/// "bytes": "L2hvbWUvdWJ1bnR1L2xpYv8ucnM="
/// }
/// }
/// ```
///
/// This same representation is used for reporting matches as well.
///
/// The printer guarantees that the `text` field is used whenever the
/// underlying bytes are valid UTF-8.
///
/// ## Wire format
///
/// This section documents the wire format emitted by this printer, starting
/// with the four types of messages.
///
/// Each message has its own format, and is contained inside an envelope that
/// indicates the type of message. The envelope has these fields:
///
/// * **type** - A string indicating the type of this message. It may be one
/// of four possible strings: `begin`, `end`, `match` or `context`. This
/// list may expand over time.
/// * **data** - The actual message data. The format of this field depends on
/// the value of `type`. The possible message formats are
/// [`begin`](#message-begin),
/// [`end`](#message-end),
/// [`match`](#message-match),
/// [`context`](#message-context).
///
/// #### Message: **begin**
///
/// This message indicates that a search has begun. It has these fields:
///
/// * **path** - An
/// [arbitrary data object](#object-arbitrary-data)
/// representing the file path corresponding to the search, if one is
/// present. If no file path is available, then this field is `null`.
///
/// #### Message: **end**
///
/// This message indicates that a search has finished. It has these fields:
///
/// * **path** - An
/// [arbitrary data object](#object-arbitrary-data)
/// representing the file path corresponding to the search, if one is
/// present. If no file path is available, then this field is `null`.
/// * **binary_offset** - The absolute offset in the data searched
/// corresponding to the place at which binary data was detected. If no
/// binary data was detected (or if binary detection was disabled), then this
/// field is `null`.
/// * **stats** - A [`stats` object](#object-stats) that contains summary
/// statistics for the previous search.
///
/// #### Message: **match**
///
/// This message indicates that a match has been found. A match generally
/// corresponds to a single line of text, although it may correspond to
/// multiple lines if the search can emit matches over multiple lines. It
/// has these fields:
///
/// * **path** - An
/// [arbitrary data object](#object-arbitrary-data)
/// representing the file path corresponding to the search, if one is
/// present. If no file path is available, then this field is `null`.
/// * **lines** - An
/// [arbitrary data object](#object-arbitrary-data)
/// representing one or more lines contained in this match.
/// * **line_number** - If the searcher has been configured to report line
/// numbers, then this corresponds to the line number of the first line
/// in `lines`. If no line numbers are available, then this is `null`.
/// * **absolute_offset** - The absolute byte offset corresponding to the start
/// of `lines` in the data being searched.
/// * **submatches** - An array of [`submatch` objects](#object-submatch)
/// corresponding to matches in `lines`. The offsets included in each
/// `submatch` correspond to byte offsets into `lines`. (If `lines` is base64
/// encoded, then the byte offsets correspond to the data after base64
/// decoding.) The `submatch` objects are guaranteed to be sorted by their
/// starting offsets. Note that it is possible for this array to be empty,
/// for example, when searching reports inverted matches.
///
/// #### Message: **context**
///
/// This message indicates that a contextual line has been found. A contextual
/// line is a line that doesn't contain a match, but is generally adjacent to
/// a line that does contain a match. The precise way in which contextual lines
/// are reported is determined by the searcher. It has these fields, which are
/// exactly the same fields found in a [`match`](#message-match):
///
/// * **path** - An
/// [arbitrary data object](#object-arbitrary-data)
/// representing the file path corresponding to the search, if one is
/// present. If no file path is available, then this field is `null`.
/// * **lines** - An
/// [arbitrary data object](#object-arbitrary-data)
/// representing one or more lines contained in this context. This includes
/// line terminators, if they're present.
/// * **line_number** - If the searcher has been configured to report line
/// numbers, then this corresponds to the line number of the first line
/// in `lines`. If no line numbers are available, then this is `null`.
/// * **absolute_offset** - The absolute byte offset corresponding to the start
/// of `lines` in the data being searched.
/// * **submatches** - An array of [`submatch` objects](#object-submatch)
/// corresponding to matches in `lines`. The offsets included in each
/// `submatch` correspond to byte offsets into `lines`. (If `lines` is base64
/// encoded, then the byte offsets correspond to the data after base64
/// decoding.) The `submatch` objects are guaranteed to be sorted by
/// their starting offsets. Note that it is possible for this array to be
/// non-empty, for example, when searching reports inverted matches such that
/// the original matcher could match things in the contextual lines.
///
/// #### Object: **submatch**
///
/// This object describes submatches found within `match` or `context`
/// messages. The `start` and `end` fields indicate the half-open interval on
/// which the match occurs (`start` is included, but `end` is not). It is
/// guaranteed that `start <= end`. It has these fields:
///
/// * **match** - An
/// [arbitrary data object](#object-arbitrary-data)
/// corresponding to the text in this submatch.
/// * **start** - A byte offset indicating the start of this match. This offset
/// is generally reported in terms of the parent object's data. For example,
/// the `lines` field in the
/// [`match`](#message-match) or [`context`](#message-context)
/// messages.
/// * **end** - A byte offset indicating the end of this match. This offset
/// is generally reported in terms of the parent object's data. For example,
/// the `lines` field in the
/// [`match`](#message-match) or [`context`](#message-context)
/// messages.
///
/// #### Object: **stats**
///
/// This object is included in messages and contains summary statistics about
/// a search. It has these fields:
///
/// * **elapsed** - A [`duration` object](#object-duration) describing the
/// length of time that elapsed while performing the search.
/// * **searches** - The number of searches that have run. For this printer,
/// this value is always `1`. (Implementations may emit additional message
/// types that use this same `stats` object that represents summary
/// statistics over multiple searches.)
/// * **searches_with_match** - The number of searches that have run that have
/// found at least one match. This is never more than `searches`.
/// * **bytes_searched** - The total number of bytes that have been searched.
/// * **bytes_printed** - The total number of bytes that have been printed.
/// This includes everything emitted by this printer.
/// * **matched_lines** - The total number of lines that participated in a
/// match. When matches may contain multiple lines, then this includes every
/// line that is part of every match.
/// * **matches** - The total number of matches. There may be multiple matches
/// per line. When matches may contain multiple lines, each match is counted
/// only once, regardless of how many lines it spans.
///
/// #### Object: **duration**
///
/// This object includes a few fields for describing a duration. Two of its
/// fields, `secs` and `nanos`, can be combined to give nanosecond precision
/// on systems that support it. It has these fields:
///
/// * **secs** - A whole number of seconds indicating the length of this
/// duration.
/// * **nanos** - A fractional part of this duration represent by nanoseconds.
/// If nanosecond precision isn't supported, then this is typically rounded
/// up to the nearest number of nanoseconds.
/// * **human** - A human readable string describing the length of the
/// duration. The format of the string is itself unspecified.
///
/// #### Object: **arbitrary data**
///
/// This object is used whenever arbitrary data needs to be represented as a
/// JSON value. This object contains two fields, where generally only one of
/// the fields is present:
///
/// * **text** - A normal JSON string that is UTF-8 encoded. This field is
/// populated if and only if the underlying data is valid UTF-8.
/// * **bytes** - A normal JSON string that is a base64 encoding of the
/// underlying bytes.
///
/// More information on the motivation for this representation can be seen in
/// the section [text encoding](#text-encoding) above.
///
/// ## Example
///
/// This section shows a small example that includes all message types.
///
/// Here's the file we want to search, located at `/home/andrew/sherlock`:
///
/// ```text
/// For the Doctor Watsons of this world, as opposed to the Sherlock
/// Holmeses, success in the province of detective work must always
/// be, to a very large extent, the result of luck. Sherlock Holmes
/// can extract a clew from a wisp of straw or a flake of cigar ash;
/// but Doctor Watson has to have it taken out for him and dusted,
/// and exhibited clearly, with a label attached.
/// ```
///
/// Searching for `Watson` with a `before_context` of `1` with line numbers
/// enabled shows something like this using the standard printer:
///
/// ```text
/// sherlock:1:For the Doctor Watsons of this world, as opposed to the Sherlock
/// --
/// sherlock-4-can extract a clew from a wisp of straw or a flake of cigar ash;
/// sherlock:5:but Doctor Watson has to have it taken out for him and dusted,
/// ```
///
/// Here's what the same search looks like using the JSON wire format described
/// above, where in we show semi-prettified JSON (instead of a strict JSON
/// Lines format), for illustrative purposes:
///
/// ```json
/// {
/// "type": "begin",
/// "data": {
/// "path": {"text": "/home/andrew/sherlock"}}
/// }
/// }
/// {
/// "type": "match",
/// "data": {
/// "path": {"text": "/home/andrew/sherlock"},
/// "lines": {"text": "For the Doctor Watsons of this world, as opposed to the Sherlock\n"},
/// "line_number": 1,
/// "absolute_offset": 0,
/// "submatches": [
/// {"match": {"text": "Watson"}, "start": 15, "end": 21}
/// ]
/// }
/// }
/// {
/// "type": "context",
/// "data": {
/// "path": {"text": "/home/andrew/sherlock"},
/// "lines": {"text": "can extract a clew from a wisp of straw or a flake of cigar ash;\n"},
/// "line_number": 4,
/// "absolute_offset": 193,
/// "submatches": []
/// }
/// }
/// {
/// "type": "match",
/// "data": {
/// "path": {"text": "/home/andrew/sherlock"},
/// "lines": {"text": "but Doctor Watson has to have it taken out for him and dusted,\n"},
/// "line_number": 5,
/// "absolute_offset": 258,
/// "submatches": [
/// {"match": {"text": "Watson"}, "start": 11, "end": 17}
/// ]
/// }
/// }
/// {
/// "type": "end",
/// "data": {
/// "path": {"text": "/home/andrew/sherlock"},
/// "binary_offset": null,
/// "stats": {
/// "elapsed": {"secs": 0, "nanos": 36296, "human": "0.0000s"},
/// "searches": 1,
/// "searches_with_match": 1,
/// "bytes_searched": 367,
/// "bytes_printed": 1151,
/// "matched_lines": 2,
/// "matches": 2
/// }
/// }
/// }
/// ```
#[derive(Debug)]
pub struct JSON<W> {
config: Config,
wtr: CounterWriter<W>,
matches: Vec<Match>,
}
impl<W: io::Write> JSON<W> {
/// Return a JSON lines printer with a default configuration that writes
/// matches to the given writer.
pub fn new(wtr: W) -> JSON<W> {
JSONBuilder::new().build(wtr)
}
/// Return an implementation of `Sink` for the JSON printer.
///
/// This does not associate the printer with a file path, which means this
/// implementation will never print a file path along with the matches.
pub fn sink<'s, M: Matcher>(
&'s mut self,
matcher: M,
) -> JSONSink<'static, 's, M, W> {
JSONSink {
matcher,
json: self,
path: None,
start_time: Instant::now(),
match_count: 0,
after_context_remaining: 0,
binary_byte_offset: None,
begin_printed: false,
stats: Stats::new(),
}
}
/// Return an implementation of `Sink` associated with a file path.
///
/// When the printer is associated with a path, then it may, depending on
/// its configuration, print the path along with the matches found.
pub fn sink_with_path<'p, 's, M, P>(
&'s mut self,
matcher: M,
path: &'p P,
) -> JSONSink<'p, 's, M, W>
where
M: Matcher,
P: ?Sized + AsRef<Path>,
{
JSONSink {
matcher,
json: self,
path: Some(path.as_ref()),
start_time: Instant::now(),
match_count: 0,
after_context_remaining: 0,
binary_byte_offset: None,
begin_printed: false,
stats: Stats::new(),
}
}
/// Write the given message followed by a new line. The new line is
/// determined from the configuration of the given searcher.
fn write_message(
&mut self,
message: &jsont::Message<'_>,
) -> io::Result<()> {
if self.config.pretty {
json::to_writer_pretty(&mut self.wtr, message)?;
} else {
json::to_writer(&mut self.wtr, message)?;
}
self.wtr.write(&[b'\n'])?;
Ok(())
}
}
impl<W> JSON<W> {
/// Returns true if and only if this printer has written at least one byte
/// to the underlying writer during any of the previous searches.
pub fn has_written(&self) -> bool {
self.wtr.total_count() > 0
}
/// Return a mutable reference to the underlying writer.
pub fn get_mut(&mut self) -> &mut W {
self.wtr.get_mut()
}
/// Consume this printer and return back ownership of the underlying
/// writer.
pub fn into_inner(self) -> W {
self.wtr.into_inner()
}
}
/// An implementation of `Sink` associated with a matcher and an optional file
/// path for the JSON printer.
///
/// This type is generic over a few type parameters:
///
/// * `'p` refers to the lifetime of the file path, if one is provided. When
/// no file path is given, then this is `'static`.
/// * `'s` refers to the lifetime of the [`JSON`] printer that this type
/// borrows.
/// * `M` refers to the type of matcher used by
/// `grep_searcher::Searcher` that is reporting results to this sink.
/// * `W` refers to the underlying writer that this printer is writing its
/// output to.
#[derive(Debug)]
pub struct JSONSink<'p, 's, M: Matcher, W> {
matcher: M,
json: &'s mut JSON<W>,
path: Option<&'p Path>,
start_time: Instant,
match_count: u64,
after_context_remaining: u64,
binary_byte_offset: Option<u64>,
begin_printed: bool,
stats: Stats,
}
impl<'p, 's, M: Matcher, W: io::Write> JSONSink<'p, 's, M, W> {
/// Returns true if and only if this printer received a match in the
/// previous search.
///
/// This is unaffected by the result of searches before the previous
/// search.
pub fn has_match(&self) -> bool {
self.match_count > 0
}
/// Return the total number of matches reported to this sink.
///
/// This corresponds to the number of times `Sink::matched` is called.
pub fn match_count(&self) -> u64 {
self.match_count
}
/// If binary data was found in the previous search, this returns the
/// offset at which the binary data was first detected.
///
/// The offset returned is an absolute offset relative to the entire
/// set of bytes searched.
///
/// This is unaffected by the result of searches before the previous
/// search. e.g., If the search prior to the previous search found binary
/// data but the previous search found no binary data, then this will
/// return `None`.
pub fn binary_byte_offset(&self) -> Option<u64> {
self.binary_byte_offset
}
/// Return a reference to the stats produced by the printer for all
/// searches executed on this sink.
pub fn stats(&self) -> &Stats {
&self.stats
}
/// Execute the matcher over the given bytes and record the match
/// locations if the current configuration demands match granularity.
fn record_matches(
&mut self,
searcher: &Searcher,
bytes: &[u8],
range: std::ops::Range<usize>,
) -> io::Result<()> {
self.json.matches.clear();
// If printing requires knowing the location of each individual match,
// then compute and stored those right now for use later. While this
// adds an extra copy for storing the matches, we do amortize the
// allocation for it and this greatly simplifies the printing logic to
// the extent that it's easy to ensure that we never do more than
// one search to find the matches.
let matches = &mut self.json.matches;
find_iter_at_in_context(
searcher,
&self.matcher,
bytes,
range.clone(),
|m| {
let (s, e) = (m.start() - range.start, m.end() - range.start);
matches.push(Match::new(s, e));
true
},
)?;
// Don't report empty matches appearing at the end of the bytes.
if !matches.is_empty()
&& matches.last().unwrap().is_empty()
&& matches.last().unwrap().start() >= bytes.len()
{
matches.pop().unwrap();
}
Ok(())
}
/// Returns true if this printer should quit.
///
/// This implements the logic for handling quitting after seeing a certain
/// amount of matches. In most cases, the logic is simple, but we must
/// permit all "after" contextual lines to print after reaching the limit.
fn should_quit(&self) -> bool {
let limit = match self.json.config.max_matches {
None => return false,
Some(limit) => limit,
};
if self.match_count < limit {
return false;
}
self.after_context_remaining == 0
}
/// Returns whether the current match count exceeds the configured limit.
/// If there is no limit, then this always returns false.
fn match_more_than_limit(&self) -> bool {
let limit = match self.json.config.max_matches {
None => return false,
Some(limit) => limit,
};
self.match_count > limit
}
/// Write the "begin" message.
fn write_begin_message(&mut self) -> io::Result<()> {
if self.begin_printed {
return Ok(());
}
let msg = jsont::Message::Begin(jsont::Begin { path: self.path });
self.json.write_message(&msg)?;
self.begin_printed = true;
Ok(())
}
}
impl<'p, 's, M: Matcher, W: io::Write> Sink for JSONSink<'p, 's, M, W> {
type Error = io::Error;
fn matched(
&mut self,
searcher: &Searcher,
mat: &SinkMatch<'_>,
) -> Result<bool, io::Error> {
self.write_begin_message()?;
self.match_count += 1;
// When we've exceeded our match count, then the remaining context
// lines should not be reset, but instead, decremented. This avoids a
// bug where we display more matches than a configured limit. The main
// idea here is that 'matched' might be called again while printing
// an after-context line. In that case, we should treat this as a
// contextual line rather than a matching line for the purposes of
// termination.
if self.match_more_than_limit() {
self.after_context_remaining =
self.after_context_remaining.saturating_sub(1);
} else {
self.after_context_remaining = searcher.after_context() as u64;
}
self.record_matches(
searcher,
mat.buffer(),
mat.bytes_range_in_buffer(),
)?;
self.stats.add_matches(self.json.matches.len() as u64);
self.stats.add_matched_lines(mat.lines().count() as u64);
let submatches = SubMatches::new(mat.bytes(), &self.json.matches);
let msg = jsont::Message::Match(jsont::Match {
path: self.path,
lines: mat.bytes(),
line_number: mat.line_number(),
absolute_offset: mat.absolute_byte_offset(),
submatches: submatches.as_slice(),
});
self.json.write_message(&msg)?;
Ok(!self.should_quit())
}
fn context(
&mut self,
searcher: &Searcher,
ctx: &SinkContext<'_>,
) -> Result<bool, io::Error> {
self.write_begin_message()?;
self.json.matches.clear();
if ctx.kind() == &SinkContextKind::After {
self.after_context_remaining =
self.after_context_remaining.saturating_sub(1);
}
let submatches = if searcher.invert_match() {
self.record_matches(searcher, ctx.bytes(), 0..ctx.bytes().len())?;
SubMatches::new(ctx.bytes(), &self.json.matches)
} else {
SubMatches::empty()
};
let msg = jsont::Message::Context(jsont::Context {
path: self.path,
lines: ctx.bytes(),
line_number: ctx.line_number(),
absolute_offset: ctx.absolute_byte_offset(),
submatches: submatches.as_slice(),
});
self.json.write_message(&msg)?;
Ok(!self.should_quit())
}
fn begin(&mut self, _searcher: &Searcher) -> Result<bool, io::Error> {
self.json.wtr.reset_count();
self.start_time = Instant::now();
self.match_count = 0;
self.after_context_remaining = 0;
self.binary_byte_offset = None;
if self.json.config.max_matches == Some(0) {
return Ok(false);
}
if !self.json.config.always_begin_end {
return Ok(true);
}
self.write_begin_message()?;
Ok(true)
}
fn finish(
&mut self,
_searcher: &Searcher,
finish: &SinkFinish,
) -> Result<(), io::Error> {
if !self.begin_printed {
return Ok(());
}
self.binary_byte_offset = finish.binary_byte_offset();
self.stats.add_elapsed(self.start_time.elapsed());
self.stats.add_searches(1);
if self.match_count > 0 {
self.stats.add_searches_with_match(1);
}
self.stats.add_bytes_searched(finish.byte_count());
self.stats.add_bytes_printed(self.json.wtr.count());
let msg = jsont::Message::End(jsont::End {
path: self.path,
binary_offset: finish.binary_byte_offset(),
stats: self.stats.clone(),
});
self.json.write_message(&msg)?;
Ok(())
}
}
/// SubMatches represents a set of matches in a contiguous range of bytes.
///
/// A simpler representation for this would just simply be `Vec<SubMatch>`,
/// but the common case is exactly one match per range of bytes, which we
/// specialize here using a fixed size array without any allocation.
enum SubMatches<'a> {
Empty,
Small([jsont::SubMatch<'a>; 1]),
Big(Vec<jsont::SubMatch<'a>>),
}
impl<'a> SubMatches<'a> {
/// Create a new set of match ranges from a set of matches and the
/// corresponding bytes that those matches apply to.
fn new(bytes: &'a [u8], matches: &[Match]) -> SubMatches<'a> {
if matches.len() == 1 {
let mat = matches[0];
SubMatches::Small([jsont::SubMatch {
m: &bytes[mat],
start: mat.start(),
end: mat.end(),
}])
} else {
let mut match_ranges = vec![];
for &mat in matches {
match_ranges.push(jsont::SubMatch {
m: &bytes[mat],
start: mat.start(),
end: mat.end(),
});
}
SubMatches::Big(match_ranges)
}
}
/// Create an empty set of match ranges.
fn empty() -> SubMatches<'static> {
SubMatches::Empty
}
/// Return this set of match ranges as a slice.
fn as_slice(&self) -> &[jsont::SubMatch<'_>] {
match *self {
SubMatches::Empty => &[],
SubMatches::Small(ref x) => x,
SubMatches::Big(ref x) => x,
}
}
}
#[cfg(test)]
mod tests {
use grep_matcher::LineTerminator;
use grep_regex::{RegexMatcher, RegexMatcherBuilder};
use grep_searcher::SearcherBuilder;
use super::{JSONBuilder, JSON};
const SHERLOCK: &'static [u8] = b"\
For the Doctor Watsons of this world, as opposed to the Sherlock
Holmeses, success in the province of detective work must always
be, to a very large extent, the result of luck. Sherlock Holmes
can extract a clew from a wisp of straw or a flake of cigar ash;
but Doctor Watson has to have it taken out for him and dusted,
and exhibited clearly, with a label attached.
";
fn printer_contents(printer: &mut JSON<Vec<u8>>) -> String {
String::from_utf8(printer.get_mut().to_owned()).unwrap()
}
#[test]
fn binary_detection() {
use grep_searcher::BinaryDetection;
const BINARY: &'static [u8] = b"\
For the Doctor Watsons of this world, as opposed to the Sherlock
Holmeses, success in the province of detective work must always
be, to a very large extent, the result of luck. Sherlock Holmes
can extract a clew \x00 from a wisp of straw or a flake of cigar ash;
but Doctor Watson has to have it taken out for him and dusted,
and exhibited clearly, with a label attached.\
";
let matcher = RegexMatcher::new(r"Watson").unwrap();
let mut printer = JSONBuilder::new().build(vec![]);
SearcherBuilder::new()
.binary_detection(BinaryDetection::quit(b'\x00'))
.heap_limit(Some(80))
.build()
.search_reader(&matcher, BINARY, printer.sink(&matcher))
.unwrap();
let got = printer_contents(&mut printer);
assert_eq!(got.lines().count(), 3);
let last = got.lines().last().unwrap();
assert!(last.contains(r#""binary_offset":212,"#));
}
#[test]
fn max_matches() {
let matcher = RegexMatcher::new(r"Watson").unwrap();
let mut printer =
JSONBuilder::new().max_matches(Some(1)).build(vec![]);
SearcherBuilder::new()
.build()
.search_reader(&matcher, SHERLOCK, printer.sink(&matcher))
.unwrap();
let got = printer_contents(&mut printer);
assert_eq!(got.lines().count(), 3);
}
#[test]
fn max_matches_after_context() {
let haystack = "\
a
b
c
d
e
d
e
d
e
d
e
";
let matcher = RegexMatcher::new(r"d").unwrap();
let mut printer =
JSONBuilder::new().max_matches(Some(1)).build(vec![]);
SearcherBuilder::new()
.after_context(2)
.build()
.search_reader(
&matcher,
haystack.as_bytes(),
printer.sink(&matcher),
)
.unwrap();
let got = printer_contents(&mut printer);
assert_eq!(got.lines().count(), 5);
}
#[test]
fn no_match() {
let matcher = RegexMatcher::new(r"DOES NOT MATCH").unwrap();
let mut printer = JSONBuilder::new().build(vec![]);
SearcherBuilder::new()
.build()
.search_reader(&matcher, SHERLOCK, printer.sink(&matcher))
.unwrap();
let got = printer_contents(&mut printer);
assert!(got.is_empty());
}
#[test]
fn always_begin_end_no_match() {
let matcher = RegexMatcher::new(r"DOES NOT MATCH").unwrap();
let mut printer =
JSONBuilder::new().always_begin_end(true).build(vec![]);
SearcherBuilder::new()
.build()
.search_reader(&matcher, SHERLOCK, printer.sink(&matcher))
.unwrap();
let got = printer_contents(&mut printer);
assert_eq!(got.lines().count(), 2);
assert!(got.contains("begin") && got.contains("end"));
}
#[test]
fn missing_crlf() {
let haystack = "test\r\n".as_bytes();
let matcher = RegexMatcherBuilder::new().build("test").unwrap();
let mut printer = JSONBuilder::new().build(vec![]);
SearcherBuilder::new()
.build()
.search_reader(&matcher, haystack, printer.sink(&matcher))
.unwrap();
let got = printer_contents(&mut printer);
assert_eq!(got.lines().count(), 3);
assert!(
got.lines().nth(1).unwrap().contains(r"test\r\n"),
r"missing 'test\r\n' in '{}'",
got.lines().nth(1).unwrap(),
);
let matcher =
RegexMatcherBuilder::new().crlf(true).build("test").unwrap();
let mut printer = JSONBuilder::new().build(vec![]);
SearcherBuilder::new()
.line_terminator(LineTerminator::crlf())
.build()
.search_reader(&matcher, haystack, printer.sink(&matcher))
.unwrap();
let got = printer_contents(&mut printer);
assert_eq!(got.lines().count(), 3);
assert!(
got.lines().nth(1).unwrap().contains(r"test\r\n"),
r"missing 'test\r\n' in '{}'",
got.lines().nth(1).unwrap(),
);
}
}