slice-file - npm Package Compare versions

Comparing version 0.0.0 to 0.1.0

index.js

@@ -5,2 +5,3 @@ var fs = require('fs');
 var inherits = require('inherits');
+var split = require('split');
 
@@ -33,2 +34,4 @@ var nextTick = typeof setImmediate === 'function'
     this.bufsize = opts.bufsize || 4 * 1024;
+    this.flags = opts.flags;
+    this.mode = opts.mode;
 }
@@ -41,3 +44,3 @@
     if (self.fd === undefined) {
-        return self.on('open', self._read.bind(self, start, end, cb));
+        return self.once('open', self._read.bind(self, start, end, cb));
     }
@@ -103,2 +106,13 @@ if (start === undefined) start = 0;
 
+FA.prototype._stat = function (cb) {
+    var self = this;
+    fs.stat(self.file, function (err, stat) {
+        if (err) return cb && cb(err);
+        
+        self.stat = stat;
+        self.emit('stat', stat);
+        if (cb) cb(null, stat);
+    });
+};
+
 FA.prototype._readReverse = function (start, end, cb) {
@@ -112,8 +126,4 @@ var self = this;
     if (self.stat === undefined) {
-        fs.stat(self.file, function (err, stat) {
-            if (err) return cb(err);
-            self.stat = stat;
-            self.emit('stat', stat);
-        });
-        return self.once('stat', function () {
+        return self._stat(function (err) {
+            if (err) cb(err);
             self._readReverse(start, end, cb)
@@ -220,1 +230,76 @@ });
 };
+
+FA.prototype.follow = function (start, end) {
+    var self = this;
+    var tr = through();
+    tr.close = function () {
+        this.closed = true;
+        this.emit('close');
+    };
+    
+    var slice = this.slice(start, end);
+    var writing = false;
+    var changed = false;
+    
+    slice.once('end', function () {
+        if (tr.closed) return;
+        var w = fs.watch(self.file, { fd: self.fd });
+        tr.once('close', function () { w.close() });
+        self.once('close', function () { w.close() });
+        
+        if (!self.stat) self._stat(onstat);
+        else onstat(null, self.stat);
+        
+        w.on('change', function (type) {
+            if (type !== 'change') return;
+            if (!writing) self._stat(onstat);
+            changed = true;
+        });
+        
+    });
+    var lastStat = null;
+    slice.pipe(tr, { end: false });
+    self.once('close', function () { tr.queue(null) });
+    tr.once('close', function () { tr.queue(null) });
+    
+    return tr.pipe(split())
+        .pipe(through(function (line) { this.queue(line + '\n') }))
+    ;
+    
+    function onstat (err, stat) {
+        if (err) return tr.emit('error', err);
+        if (!lastStat) return lastStat = stat;
+        
+        if (stat.size < lastStat.size) {
+            tr.emit('truncate', lastStat.size - stat.size);
+        }
+        else if (stat.size > lastStat.size) {
+            writing = true;
+            var stream = fs.createReadStream(self.file, {
+                //fd: self.fd,
+                start: lastStat.size,
+                flags: self.flags,
+                mode: self.mode,
+                //autoClose: false,
+                bufferSize: self.bufsize
+            });
+            stream.on('error', function (err) { tr.emit('error', err) });
+            stream.on('end', function () {
+                if (changed) self._stat(onstat);
+                writing = false;
+                changed = false;
+            });
+            stream.pipe(tr, { end: false });
+        }
+        
+        lastStat = stat;
+    }
+};
+
+FA.prototype.close = function () {
+    var self = this;
+    if (self.fd === undefined) return self.once('open', self.close);
+    fs.close(self.fd, function () {
+        self.emit('close');
+    });
+};

package.json

 {
     "name": "slice-file",
-    "version": "0.0.0",
+    "version": "0.1.0",
     "description": "stream file slices by line number indexes",
@@ -8,3 +8,4 @@ "main": "index.js",
         "inherits": "~1.0.0",
-        "through": "~2.2.7"
+        "through": "~2.2.7",
+        "split": "~0.2.1"
     },
@@ -11,0 +12,0 @@ "devDependencies": {

New alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Environment variable access

Supply chain risk

Package accesses environment variables, which may be a sign of credential stuffing or data theft.

Found 1 instance in 1 package

Fixed alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

20992

increased by35.1%

Number of package files

18

increased by20%

Lines of code

504

increased by30.23%

Number of lines in readme file

160

increased by70.21%

Worsened metrics

Dependency count

3

increased by50%

Number of low supply chain risk alerts

6

increased by50%

Dependency changes

• + Addedsplit@~0.2.1

• + Addedsplit@0.2.10(transitive)