level-hooks - npm Package Compare versions

Comparing version 2.0.0 to 3.0.0

index.js

@@ -6,105 +6,119 @@
 module.exports = function (db) {
-  if(db) return hooks(db)
 
-  function hooks (db) {
+  if(db.hooks) {
+    return     
+  }
 
-    if(db.hooks) {
-      return     
-    }
+  var posthooks = []
+  var prehooks  = []
 
-    var posthooks = []
-    var prehooks  = []
+  function getPrefix (p) {
+    return p && (
+        'string' ===   typeof p        ? p
+      : 'string' ===   typeof p.prefix ? p.prefix
+      : 'function' === typeof p.prefix ? p.prefix()
+      :                                  ''
+      )
+  }
 
-    function getPrefix (p) {
-      return p && (
-          'string' ===   typeof p        ? p
-        : 'string' ===   typeof p.prefix ? p.prefix
-        : 'function' === typeof p.prefix ? p.prefix()
-        :                                  ''
-        )
-    }
+  function checker(range) {
+    if ('string' === typeof range)
+      return function (key) {
+        return key.indexOf(range) == 0
+      }
+    else if(range instanceof RegExp)
+      return function (key) {
+        return range.test(key)
+      }
+    else if('object' === typeof range)
+      return function (key) {
+        return key >= range.start && key <= range.end
+      }
+    else if('function' === typeof range)
+      return range
+  }
 
-    db.hooks = {
-      post: function (hook) {
-        db.on('hooks:post', hook)
-        return db
-      },
-      pre: function (prefix, hook) {
-        if(!hook) hook = prefix, prefix = ''
-        prehooks.push({prefix: getPrefix(prefix), hook: hook})
-        return db
-      },
-      posthooks: posthooks,
-      prehooks: prehooks
-    }
+  db.hooks = {
+    post: function (hook) {
+      if(!hook) hook = prefix, prefix = ''
+      posthooks.push({test: checker(prefix), hook: hook})
+      return db
+    },
+    pre: function (prefix, hook) {
+      if(!hook) hook = prefix, prefix = ''
+      prehooks.push({test: checker(prefix), hook: hook})
+      return db
+    },
+    posthooks: posthooks,
+    prehooks: prehooks
+  }
 
-    //POST HOOKS
+  //POST HOOKS
 
-    function each (e) {
-      if(e && e.type)
-        db.emit('hooks:post', e)
+  function each (e) {
+    if(e && e.type) {
+      posthooks.forEach(function (h) {
+        if(h.test(e.key)) h.hook(e)
+      })
     }
+  }
 
-    db.on('put', function (key, val) {
-      each({type: 'put', key: key, value: val})
-    })
-    db.on('del', function (key, val) {
-      each({type: 'del', key: key, value: val})
-    })
-    db.on('batch', function onBatch (ary) {
-      ary.forEach(each)
-    })
+  db.on('put', function (key, val) {
+    each({type: 'put', key: key, value: val})
+  })
+  db.on('del', function (key, val) {
+    each({type: 'del', key: key, value: val})
+  })
+  db.on('batch', function onBatch (ary) {
+    ary.forEach(each)
+  })
 
-    //PRE HOOKS
+  //PRE HOOKS
 
-    var put = db.put
-    var del = db.del
-    var batch = db.batch
+  var put = db.put
+  var del = db.del
+  var batch = db.batch
 
-    function callHooks (isBatch, b, opts, cb) {
+  function callHooks (isBatch, b, opts, cb) {
 
-      b.forEach(function hook(e, i) {
-        prehooks.forEach(function (h) {
-          if(e.key.indexOf(h.prefix) == 0)
-            h.hook(e, function (ch, db) {
-              if(ch === false)
-                return delete b[i]
-              var prefix = getPrefix(db) || h.prefix || ''
-              ch.key = prefix + ch.key
-              console.log('batch - add', ch)
-              b.push(ch)
-              hook(ch, b.length - 1)            
-            })
-        })
+    b.forEach(function hook(e, i) {
+      prehooks.forEach(function (h) {
+        if(h.test(e.key))
+          h.hook(e, function (ch, db) {
+            if(ch === false)
+              return delete b[i]
+            var prefix = getPrefix(db) || h.prefix || ''
+            ch.key = prefix + ch.key
+            b.push(ch)
+            hook(ch, b.length - 1)            
+          })
       })
+    })
 
-      b = b.filter(function (e) {
-        return e && e.type //filter out empty items
-      })
+    b = b.filter(function (e) {
+      return e && e.type //filter out empty items
+    })
 
-      if(b.length == 1 && !isBatch) {
-        var change = b[0]
-        return change.type == 'put' 
-          ? put.call(db, change.key, change.value, opts, cb) 
-          : del.call(db, change.key, opts, cb)  
-      }
-      return batch.call(db, b, opts, cb)
+    if(b.length == 1 && !isBatch) {
+      var change = b[0]
+      return change.type == 'put' 
+        ? put.call(db, change.key, change.value, opts, cb) 
+        : del.call(db, change.key, opts, cb)  
     }
+    return batch.call(db, b, opts, cb)
+  }
 
-    db.put = function (key, value, opts, cb ) {
-      var batch = [{key: key, value: value, type: 'put'}]
-      return callHooks(false, batch, opts, cb)
-    }
+  db.put = function (key, value, opts, cb ) {
+    var batch = [{key: key, value: value, type: 'put'}]
+    return callHooks(false, batch, opts, cb)
+  }
 
-    db.del = function (key, opts, cb) {
-      var batch = [{key: key, type: 'del'}]
-      return callHooks(false, batch, opts, cb)
-    }
+  db.del = function (key, opts, cb) {
+    var batch = [{key: key, type: 'del'}]
+    return callHooks(false, batch, opts, cb)
+  }
 
-    db.batch = function (batch, opts, cb) {
-      return callHooks(true, batch, opts, cb)
-    }
+  db.batch = function (batch, opts, cb) {
+    return callHooks(true, batch, opts, cb)
   }
-
-  return hooks
 }

package.json

 {
   "name": "level-hooks",
   "description": "pre/post hooks for leveldb",
-  "version": "2.0.0",
+  "version": "3.0.0",
   "homepage": "https://github.com/dominictarr/level-hooks",
@@ -6,0 +6,0 @@ "repository": {

README.md

@@ -6,3 +6,3 @@ # Pre/Post hooks for leveldb
 ## Warning - Breaking Changes
-
+ 
 The API for implementing pre hooks has changed.
@@ -13,4 +13,10 @@ Instead of mutating an array at once, the prehook
 
-## Examlpe
+Also, attaching hooks to leveldb is now simpler
+``` js
+var Hooks = require('level-hooks')
+Hooks(db) //previously: Hooks()(db)
+```
 
+## Example
+
 ``` js
@@ -24,3 +30,3 @@ var levelup   = require('levelup')
   //install hooks onto db.
-  hooks()(db)
+  hooks(db)
 
@@ -53,2 +59,3 @@ db.hooks.pre(function (change, add) {
 })
+
 ```
@@ -58,1 +65,28 @@
 to make map-reduce durable across crashes!
+
+## API
+
+### db.hooks.pre (range?, hook(change, add(change, prefix?)))
+
+If `prefix` is a `string` or `object` that defines the range the pre-hook triggers on.
+If `prefix' is a string, then the hook only triggers on keys that _start_ with that 
+string. If the hook is an object it must be of form `{start: START, end: END}`
+
+`hook` is a function, and will be called on each item in the batch 
+(if it was a `put` or `del`, it will be called on the change)
+`change` is always of the form `{key: key, value: value, type:'put' | 'del'}`
+
+Pass additional changes to `add` to add them to the batch.
+If add is passed a string as the second argument it will prepend that prefix
+to any keys you add.
+
+To veto (remove) the current change call `add(false)`.
+
+### db.hooks.post (range?, hook)
+
+Post hooks do not offer any chance to change the value.
+but do take a range option, just like `pre`
+
+## License
+
+MIT

test/intercept.js

@@ -14,12 +14,11 @@ var rimraf  = require('rimraf')
     
-    hooks()(db)
+    hooks(db)
     var _batch = []
-    db.hooks.pre(mac(function (ch, add) {
+    //hook keys that start with a word character
+    db.hooks.pre(/^\w/, mac(function (ch, add) {
       
-      if(ch.key != 'h') {
-        _batch.push(ch)
-        var a
-        add(a = {key: 'h', value: 'hello', type: 'put'})
-        _batch.push(a)
-      }
+      _batch.push(ch)
+      var a
+      add(a = {key: '~h', value: 'hello', type: 'put'})
+      _batch.push(a)
     }).atLeast(1))
@@ -26,0 +25,0 @@

test/prehook.js

 var rimraf  = require('rimraf')
 var levelup = require('levelup')
 
-var use     = require('../use')
-var hooks   = require('..')
+var hooks   = require('../')
 
@@ -20,20 +19,19 @@ var assert  = require('assert')
 
-    use(db)
-    .use(hooks())
-    .hooks.pre(mac(function (ch, add) {
+    hooks(db)
+
+
+    db.hooks.pre(/^\w/, mac(function (ch, add) {
       //iterate backwards so you can push without breaking stuff.
       var key = ch.key
-      if(key < '~') {
-        add({
-          type: 'put', 
-          key: new Buffer('~log~'+ ++SEQ),
-          value: new Buffer(JSON.stringify({
-            type: ch.type, 
-            key: key.toString(), 
-            time: Date.now()
-          }))
-        })
+      add({
+        type: 'put', 
+        key: new Buffer('~log~'+ ++SEQ),
+        value: new Buffer(JSON.stringify({
+          type: ch.type, 
+          key: key.toString(), 
+          time: Date.now()
+        }))
+      })
+      add({type: 'put', key: new Buffer('~seq'), value: new Buffer(SEQ.toString())})
 
-        add({type: 'put', key: new Buffer('~seq'), value: new Buffer(SEQ.toString())})
-      }
     }).atLeast(1))
@@ -40,0 +38,0 @@

No alert changes

Improved metrics

Total package byte prevSize

11755

increased by4.47%

Number of lines in readme file

88

increased by62.96%

Worsened metrics

Number of package files

11

decreased by-8.33%

Lines of code

262

decreased by-4.73%

No dependency changes