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-rw-r--r--couchjs/js/views.js126
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+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+
+
+var Views = (function() {
+
+ var map_results = []; // holds temporary emitted values during doc map
+
+ function runReduce(reduceFuns, keys, values, rereduce) {
+ for (var i in reduceFuns) {
+ reduceFuns[i] = Couch.compileFunction(reduceFuns[i]);
+ };
+ var reductions = new Array(reduceFuns.length);
+ for(var i = 0; i < reduceFuns.length; i++) {
+ try {
+ reductions[i] = reduceFuns[i](keys, values, rereduce);
+ } catch (err) {
+ handleViewError(err);
+ // if the error is not fatal, ignore the results and continue
+ reductions[i] = null;
+ }
+ };
+ var reduce_line = Couch.toJSON(reductions);
+ var reduce_length = reduce_line.length;
+ // TODO make reduce_limit config into a number
+ if (State.query_config && State.query_config.reduce_limit &&
+ reduce_length > 200 && ((reduce_length * 2) > State.line_length)) {
+ var reduce_preview = "Current output: '"+(reduce_line.substring(0,100) + "'... (first 100 of "+reduce_length+" bytes)");
+ throw(["error",
+ "reduce_overflow_error",
+ "Reduce output must shrink more rapidly: "+reduce_preview]);
+ } else {
+ print("[true," + reduce_line + "]");
+ }
+ };
+
+ function handleViewError(err, doc) {
+ if (err == "fatal_error") {
+ // Only if it's a "fatal_error" do we exit. What's a fatal error?
+ // That's for the query to decide.
+ //
+ // This will make it possible for queries to completely error out,
+ // by catching their own local exception and rethrowing a
+ // fatal_error. But by default if they don't do error handling we
+ // just eat the exception and carry on.
+ //
+ // In this case we abort map processing but don't destroy the
+ // JavaScript process. If you need to destroy the JavaScript
+ // process, throw the error form matched by the block below.
+ throw(["error", "map_runtime_error", "function raised 'fatal_error'"]);
+ } else if (err[0] == "fatal") {
+ // Throwing errors of the form ["fatal","error_key","reason"]
+ // will kill the OS process. This is not normally what you want.
+ throw(err);
+ }
+ var message = "function raised exception " + err.toSource();
+ if (doc) message += " with doc._id " + doc._id;
+ log(message);
+ };
+
+ return {
+ // view helper functions
+ emit : function(key, value) {
+ map_results.push([key, value]);
+ },
+ sum : function(values) {
+ var rv = 0;
+ for (var i in values) {
+ rv += values[i];
+ }
+ return rv;
+ },
+ reduce : function(reduceFuns, kvs) {
+ var keys = new Array(kvs.length);
+ var values = new Array(kvs.length);
+ for(var i = 0; i < kvs.length; i++) {
+ keys[i] = kvs[i][0];
+ values[i] = kvs[i][1];
+ }
+ runReduce(reduceFuns, keys, values, false);
+ },
+ rereduce : function(reduceFuns, values) {
+ runReduce(reduceFuns, null, values, true);
+ },
+ mapDoc : function(doc) {
+ // Compute all the map functions against the document.
+ //
+ // Each function can output multiple key/value pairs for each document.
+ //
+ // Example output of map_doc after three functions set by add_fun cmds:
+ // [
+ // [["Key","Value"]], <- fun 1 returned 1 key value
+ // [], <- fun 2 returned 0 key values
+ // [["Key1","Value1"],["Key2","Value2"]] <- fun 3 returned 2 key values
+ // ]
+ //
+
+ Couch.recursivelySeal(doc);
+
+ var buf = [];
+ for (var i = 0; i < State.funs.length; i++) {
+ map_results = [];
+ try {
+ State.funs[i](doc);
+ buf.push(Couch.toJSON(map_results));
+ } catch (err) {
+ handleViewError(err, doc);
+ // If the error is not fatal, we treat the doc as if it
+ // did not emit anything, by buffering an empty array.
+ buf.push("[]");
+ }
+ }
+ print("[" + buf.join(", ") + "]");
+ }
+ }
+})();