{
"_mongo" : connection to YOURIP:27017{ SSL: { sslSupport: false, sslPEMKeyFile: "" } }{ SSH: { host: "", port: 22, user: "", password: "", publicKey: { publicKey: "", privateKey: "", passphrase: "" }, currentMethod: 0 } },
"_db" : mazhan_log,
"_collection" : YOURCOLLECTION,
"_ns" : "YOURCOLLECTION",
"_query" : {
},
"_fields" : null,
"_limit" : 0,
"_skip" : 0,
"_batchSize" : 0,
"_options" : 0,
"_cursor" : {
},
"_numReturned" : 50,
"_special" : false,
"_cursorSeen" : 50,
"help" : function () {
print("find() modifiers");
print("\t.sort( {...} )");
print("\t.limit( n )");
print("\t.skip( n )");
print("\t.count() - total # of objects matching query, ignores skip,limit");
print("\t.size() - total # of objects cursor would return, honors skip,limit");
print("\t.explain([verbose])");
print("\t.hint(...)");
print("\t.addOption(n) - adds op_query options -- see wire protocol");
print("\t._addSpecial(name, value) - http://dochub.mongodb.org/core/advancedqueries#AdvancedQueries-Metaqueryoperators");
print("\t.batchSize(n) - sets the number of docs to return per getMore");
print("\t.showDiskLoc() - adds a $diskLoc field to each returned object");
print("\t.min(idxDoc)");
print("\t.max(idxDoc)");
print("\nCursor methods");
print("\t.toArray() - iterates through docs and returns an array of the results");
print("\t.forEach( func )");
print("\t.map( func )");
print("\t.hasNext()");
print("\t.next()");
print("\t.objsLeftInBatch() - returns count of docs left in current batch (when exhausted, a new getMore will be issued)");
print("\t.count(applySkipLimit) - runs command at server");
print("\t.itcount() - iterates through documents and counts them");
},
"clone" : function () {
var q = new DBQuery(this._mongo, this._db, this._collection, this._ns, this._query, this._fields, this._limit, this._skip, this._batchSize, this._options);
q._special = this._special;
return q;
},
"_ensureSpecial" : function () {
if (this._special) {
return;
}
var n = {query:this._query};
this._query = n;
this._special = true;
},
"_checkModify" : function () {
if (this._cursor) {
throw "query already executed";
}
},
"_exec" : function () {
if (!this._cursor) {
assert.eq(0, this._numReturned);
this._cursor = this._mongo.find(this._ns, this._query, this._fields, this._limit, this._skip, this._batchSize, this._options);
this._cursorSeen = 0;
}
return this._cursor;
},
"limit" : function (limit) {
this._checkModify();
this._limit = limit;
return this;
},
"batchSize" : function (batchSize) {
this._checkModify();
this._batchSize = batchSize;
return this;
},
"addOption" : function (option) {
this._options |= option;
return this;
},
"skip" : function (skip) {
this._checkModify();
this._skip = skip;
return this;
},
"hasNext" : function () {
this._exec();
if (this._limit > 0 && this._cursorSeen >= this._limit) {
return false;
}
var o = this._cursor.hasNext();
return o;
},
"next" : function () {
this._exec();
var o = this._cursor.hasNext();
if (o) {
this._cursorSeen++;
} else {
throw "error hasNext: " + o;
}
var ret = this._cursor.next();
if (ret.$err && this._numReturned == 0 && !this.hasNext()) {
throw "error: " + tojson(ret);
}
this._numReturned++;
return ret;
},
"objsLeftInBatch" : function () {
this._exec();
var ret = this._cursor.objsLeftInBatch();
if (ret.$err) {
throw "error: " + tojson(ret);
}
return ret;
},
"readOnly" : function () {
this._exec();
this._cursor.readOnly();
return this;
},
"toArray" : function () {
if (this._arr) {
return this._arr;
}
var a = [];
while (this.hasNext()) {
a.push(this.next());
}
this._arr = a;
return a;
},
"count" : function (applySkipLimit) {
var cmd = {count:this._collection.getName()};
if (this._query) {
if (this._special) {
cmd.query = this._query.query;
} else {
cmd.query = this._query;
}
}
cmd.fields = this._fields || {};
if (applySkipLimit) {
if (this._limit) {
cmd.limit = this._limit;
}
if (this._skip) {
cmd.skip = this._skip;
}
}
var res = this._db.runCommand(cmd);
if (res && res.n != null) {
return res.n;
}
throw "count failed: " + tojson(res);
},
"size" : function () {
return this.count(true);
},
"countReturn" : function () {
var c = this.count();
if (this._skip) {
c = c - this._skip;
}
if (this._limit > 0 && this._limit < c) {
return this._limit;
}
return c;
},
"itcount" : function () {
var num = 0;
while (this.hasNext()) {
num++;
this.next();
}
return num;
},
"length" : function () {
return this.toArray().length;
},
"_addSpecial" : function (name, value) {
this._ensureSpecial();
this._query[name] = value;
return this;
},
"sort" : function (sortBy) {
return this._addSpecial("orderby", sortBy);
},
"hint" : function (hint) {
return this._addSpecial("$hint", hint);
},
"min" : function (min) {
return this._addSpecial("$min", min);
},
"max" : function (max) {
return this._addSpecial("$max", max);
},
"showDiskLoc" : function () {
return this._addSpecial("$showDiskLoc", true);
},
"readPref" : function (mode, tagSet) {
var readPrefObj = {mode:mode};
if (tagSet) {
readPrefObj.tags = tagSet;
}
return this._addSpecial("$readPreference", readPrefObj);
},
"forEach" : function (func) {
while (this.hasNext()) {
func(this.next());
}
},
"map" : function (func) {
var a = [];
while (this.hasNext()) {
a.push(func(this.next()));
}
return a;
},
"arrayAccess" : function (idx) {
return this.toArray()[idx];
},
"comment" : function (comment) {
var n = this.clone();
n._ensureSpecial();
n._addSpecial("$comment", comment);
return this.next();
},
"explain" : function (verbose) {
var n = this.clone();
n._ensureSpecial();
n._query.$explain = true;
n._limit = Math.abs(n._limit) * -1;
var e = n.next();
function cleanup(obj) {
if (typeof obj != "object") {
return;
}
delete obj.allPlans;
delete obj.oldPlan;
if (typeof obj.length == "number") {
for (var i = 0; i < obj.length; i++) {
cleanup(obj[i]);
}
}
if (obj.shards) {
for (var key in obj.shards) {
cleanup(obj.shards[key]);
}
}
if (obj.clauses) {
cleanup(obj.clauses);
}
}
if (!verbose) {
cleanup(e);
}
return e;
},
"snapshot" : function () {
this._ensureSpecial();
this._query.$snapshot = true;
return this;
},
"pretty" : function () {
this._prettyShell = true;
return this;
},
"shellPrint" : function () {
try {
var start = (new Date).getTime();
var n = 0;
while (this.hasNext() && n < DBQuery.shellBatchSize) {
var s = this.next();
print(s);
n++;
}
if (typeof _verboseShell !== "undefined" && _verboseShell) {
var time = (new Date).getTime() - start;
print("Fetched " + n + " record(s) in " + time + "ms");
}
if (this.hasNext()) {
___it___ = this;
} else {
___it___ = null;
}
} catch (e) {
print(e);
}
},
"toString" : function () {
return "DBQuery: " + this._ns + " -> " + tojson(this._query);
}
}
先带源码裸奔， 解读注释部分随后补充。
其实js代码很好读的，嘿嘿！！！