This is the the driver for DB.MEMORY described in Database abstraction with google apps script
The library reference is:
M96uVZRXXG_RY3c2at9V6tSz3TLx7pV4j
Reference
There’s nothing to stop us using memory as a back end database. Sounds a little unnecessary, but when you think of it this gives you all the filtering sorting and selection capabilities of a database without actually using a database. Another great benefit is that it allows you to test your database abstraction application (since the querying syntax is exactly the same) without actually using (even before selecting) a backend database and potentially using up some quota… and of course the performance is good. You can also easily combine this with an external database – just query in all the data, and do your normal queries in memory.
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var driveHandler = new cDataHandler.DataHandler('mydata',cDataHandler.dhConstants.DB.MEMORY); |
The Code
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/** wrapper */ function createDriver (handler,siloId,driverSpecific,driverOb, accessToken) { return new DriverMemory(handler,siloId,driverSpecific,driverOb, accessToken); } /** * DriverMemory * @param {cDataHandler} handler the datahandler thats calling me * @param {string} tableName this is filename * @return {DriverMemory} self */ function getLibraryInfo () { return { info: { name:'cDriverMemory', version:'2.2.0', key:'M96uVZRXXG_RY3c2at9V6tSz3TLx7pV4j', share:'https://script.google.com/d/101pVFakzEfvHquUFOmZafAzfBAGSotgH56IqVcGmWNBu7J0sweklqyCB/edit?usp=sharing', description:'in memory dbabstraction driver' }, dependencies:[ cUseful.getLibraryInfo() ] }; } // this can be used for in memory querying of a data set // a JSON object can be manipulated to provide database like characteristics // data is stored as [ {key:someuniquekey, data:{},...] var DriverMemory = function (handler,tableName,driverSpecific) { var siloId = tableName; var self = this; var dbId = driverSpecific; var parentHandler = handler; var enums = parentHandler.getEnums(); var handle, handleError, handleCode , handleIds, handleKey; var content_ = []; var transactionBox_ = null; // im able to do transactions self.transactionCapable = true; // i dont need any locking self.lockingBypass = true; // i am aware of transactions and know about the locking i should do self.transactionAware = true; /** * begins transaction and store current content * @param {string} id transaction id */ self.beginTransaction = function (id) { transactionBox_ = { id: id, content: null }; }; self.getTransactionBox = function () { return transactionBox_; }; self.transactionData = function () { self.getTransactionBox().content = parentHandler.clone(content_); return parentHandler.makeResults (enums.CODE.OK); }; /** * commits transaction * @param {string} id transaction id * @return {object} a normal result package */ self.commitTransaction = function (id) { // double check we are committing the correct transaction if (!self.isTransaction (id)) { return parentHandler.makeResults (enums.CODE.TRANSACTION_ID_MISMATCH); } // with memory there is nothing more to do- memory is already committed transactionBox_= null; return parentHandler.makeResults(enums.CODE.OK); }; /** * roll back transaction - resets memory to beginnging of transaction * @param {string} id transaction id * @return {object} a normal result package */ self.rollbackTransaction = function (id) { // double check we are committing the correct transaction if (!self.isTransaction (id)) { return parentHandler.makeResults (enums.CODE.TRANSACTION_ID_MISMATCH); } // roll back content self.makeContent(transactionBox_.content); transactionBox_= null; return parentHandler.makeResults(enums.CODE.OK); }; /** * checks that the transaction matches the one stored * @param {string} id transaction id * @return {boolean} whether id matches */ self.isTransaction = function (id) { return transactionBox_ && transactionBox_.id === id ; }; self.getType = function () { return enums.DB.MEMORY; }; self.getDbId = function () { return siloId; }; self.getParentHandler = function () { return parentHandler; }; handle = self; /** return self * @return {DriverMemory} the self */ self.getDriveHandle = function () { return handle; }; /** * DriverMemory.getTableName() * @return {string} table name or silo */ self.getTableName = function () { return siloId; }; /** * DriverMemory.getContent_() returns a copy of the content * @return {object} */ self.getContent_ = function () { return parentHandler.clone(content_) ; }; /** * DriverMemory.makeContent() sets the content * @param {object} the content * @return {DriverMemory} self */ self.makeContent = function (data) { content_ = data ; return self; }; /** * DriverMemory.takeContent() gets the content * @return {object} the content */ self.takeContent = function () { return content_ ; }; /** * DriverMemory.setContent_() takes a copy of data to be current content * @return {void} */ self.setContent_ = function (data) { content_ = parentHandler.clone(data); }; return self; }; /** create the driver version * @return {string} the driver version **/ DriverMemory.prototype.getVersion = function () { return getLibraryInfo().info.name+':'+getLibraryInfo().info.version; }; /** each saved records needs a unique key in orchestrate * @return {string} a unique key */ DriverMemory.prototype.generateKey = function () { var self = this; return self.getParentHandler().generateUniqueString(); }; /** * DriverMemory.query() * @param {object} queryOb some query object * @param {object} queryParams additional query parameters (if available) * @param {boolean} keepIds whether or not to keep driver specifc ids in the results * @return {object} results from selected handler **/ DriverMemory.prototype.query = function (queryOb,queryParams,keepIds) { var self = this; var enums = self.getParentHandler().getEnums(); var result =null,driverIds=[],handleKeys=[]; var handleCode = enums.CODE.OK, handleError=''; try { result = self.getContent_(); // apply anyfilters var pr = self.getParentHandler().processFilters (queryOb, result); handleCode =pr.handleCode; handleError = pr.handleError; if (handleCode === enums.CODE.OK) { result = pr.data; } // LIMIT & SORT & skip if (handleCode===enums.CODE.OK) { var pr = self.getParentHandler().processParams( queryParams,result); handleCode =pr.handleCode; handleError = pr.handleError; // get rid of ids if necessary if (handleCode === enums.CODE.OK) { result = pr.data.map(function(d) { if (keepIds) { driverIds.push(d.keys); handleKeys.push(d.keys); } return d.data; }); } } } catch(err) { handleError = err; handleCode = enums.CODE.DRIVER; } return self.getParentHandler().makeResults (handleCode,handleError,result,keepIds ? driverIds :null,keepIds ? handleKeys:null); }; /** * Driver.update() * @param {string} key the unique return in handleKeys for this object * @param {object} ob what to update it to * @param {string} optPlant where to pant the key in the data if required * @return {object} results from selected handler **/ DriverMemory.prototype.update = function (keys,obs,optPlant) { var self = this; var result =null; var enums = self.getParentHandler().getEnums(); var keyName = 'key'; var handleError='', handleCode=enums.CODE.OK if (!Array.isArray (obs)) obs = [obs]; if (!Array.isArray (keys)) keys = [keys]; if(keys.length !== obs.length && obs.length !== 1) { return self.getParentHandler().makeResults (enums.CODE.KEYS_AND_OBJECTS,'objects- ' + obs.length + ' keys- ' + keys.length,result); } try { // the data var content = self.getContent_(); // update each row matching a key keys.forEach (function(d,i) { // various strategies for matching the key var idx = find_(d,content,keyName); // oops no match if (idx === -1) { handleCode = enums.CODE.NOMATCH; } // update with new data and carry forward the key in the data if needed else { content[idx].data = obs.length === 1 ? obs[0] : obs[i]; if (optPlant) content[idx].data[optPlant] = d; } }); self.setContent_(content); } catch(err) { handleError = err; handleCode = enums.CODE.DRIVER; } function find_ (id,content, kName) { var idx = -1; content.some(function(d,i) { if (compareKeys_ ( d ,id ,kName )) idx = i; return idx === i; }); return idx; } return self.getParentHandler().makeResults (handleCode,handleError); }; /** * Driver.get() * @param {string} key the unique return in handleKeys for this object * @param {boolean} keepIds whether or not to keep driver specifc ids in the results * @param {string} optKeyName key name to match on (default 'key') * @return {object} results from selected handler **/ DriverMemory.prototype.get = function (keys,keepIds,optKeyName) { var self = this; var result =null; var enums = self.getParentHandler().getEnums(); var result =null; var handleError='', handleCode=enums.CODE.OK; var driverIds = [], handleKeys = []; var keyName = optKeyName || 'key'; // only returns one if (!Array.isArray(keys)) keys = [keys]; // the data result = self.getContent_().filter (function(d) { return keys.some( function(e) { return compareKeys_ (d , e ,keyName ); }); }); if (!result.length) { handleCode = enums.CODE.NOMATCH; } else { // get rid of ids if necessary result = result.map(function(d) { if (keepIds) { driverIds.push(d.keys); handleKeys.push(d.keys); } return d.data; }); } return self.getParentHandler().makeResults (handleCode,handleError,result,keepIds ? driverIds :null,keepIds ? handleKeys:null); }; /** * DriverMemory.count() * @param {object} queryOb some query object * @param {object} queryParams additional query parameters (if available) * @return {object} results from selected handler **/ DriverMemory.prototype.count = function (queryOb,queryParams) { var self = this; var enums= self.getParentHandler().getEnums(); var result =[]; var handleCode = enums.CODE.OK, handleError=''; try { // start with a query var queryResults = self.query (queryOb, queryParams ); result = [{count:queryResults.data.length}]; } catch(err) { handleError = err + "(counting "+ self.getTableName()+" in memory)"; handleCode = enums.CODE.DRIVER; } return self.getParentHandler().makeResults (handleCode,handleError,result); }; /** * DriverMemory.save() * @param {Array.object} obs array of objects to write * @return {object} results from selected handler */ DriverMemory.prototype.save = function (obs,optKey) { var self = this; var enums= self.getParentHandler().getEnums(); var handleError='', handleCode=enums.CODE.OK; var toAdd; try { var oldContent = self.getContent_(); toAdd = obs.map (function(d,i) { return self.makeMemoryEntry (d,i+oldContent.length,optKey); }); self.setContent_(oldContent.concat(toAdd)); var newContent = self.getContent_(); if (newContent.length != obs.length + oldContent.length) { handleCode = enums.CODE.DRIVER_ASSERTION; handleError = 'after saving, length was ' + newContent.length + ' but should have been ' + oldContent.length + queryResults.handleKeys.length; } // so now we need to patch the row numbers } catch(err) { handleError = cUseful.showError(err) + "(writing "+ self.getTableName()+" to memory)"; handleCode = enums.CODE.DRIVER; } var tr = self.getParentHandler().makeResults (handleCode,handleError,obs,undefined,self.getKeys(toAdd)) return tr; }; DriverMemory.prototype.getKeys = function (entries) { return (entries || []).map (function(d) { return d.keys ? {keys:d.keys} : {key:d.key}; }); }; DriverMemory.prototype.makeMemoryEntry = function (item, index, optKey) { var self = this; // this is for preserving keys between sessions var key; // this is transitional .. eventually I'll harmonize the key structure between delegated drivers since clean up at version 2.2 if (optKey) { if (item.hasOwnProperty(optKey)) { key = item[optKey]; } else { if (item.hasOwnProperty(keys)) { key = item.keys.key; } else { item = key.key; } } } else { key = self.generateKey(); } if (!key) throw 'programming error generating key'; var d = { data: item, keys: { key: key, row: index+1 } }; return d; } function compareKeys_ (item, key,keyName) { return (cUseful.isObject(key) ? key[keyName] : key) === item.keys[keyName] ; } /** * DriverMemory.remove() * @param {object} queryOb some query object * @param {object} queryParams additional query parameters (if available) * @param {object} optKeyName optional keyname to match on * @return {object} results from selected handler **/ DriverMemory.prototype.remove = function (queryOb,queryParams,optKeyName) { var self = this; var enums= self.getParentHandler().getEnums(); var result =null; var handleError='', handleCode=enums.CODE.OK; var keyName = optKeyName || 'key'; try { // start with a query var queryResults = self.query (queryOb, queryParams , true); if (handleCode === enums.CODE.OK && queryResults.data.length > 0 ) { var oldContent = self.getContent_(); self.setContent_(oldContent.filter( function(d) { return !queryResults.handleKeys.some( function (k) { return compareKeys_ (d , k ,keyName ) ; }); })); var newContent = self.getContent_(); if (oldContent.length != queryResults.handleKeys.length + newContent.length) { handleCode = enums.CODE.DRIVER_ASSERTION; handleError = 'after removing, length was ' + newContent.length + ' but should have been ' + oldContent.length - queryResults.handleKeys.length; } } } catch(err) { handleError = cUseful.showError(err) + "(writing "+ self.getTableName()+" to memory)"; handleCode = enums.CODE.DRIVER; } return self.getParentHandler().makeResults (handleCode,handleError); }; /** * DriverMemory.removeByIds() * @param {Array.string} keys array of keys to match * @param {Array.string} optKeyName optional key name to target * @return {object} results from selected handler */ DriverMemory.prototype.removeByIds = function (keys,optKeyName) { var self = this; var enums= self.getParentHandler().getEnums(); var result =null; var handleError='', handleCode=enums.CODE.OK; var keyName = optKeyName || 'key'; try { // get the current content var oldContent = self.getContent_(); self.setContent_(oldContent.filter( function(d) { return !keys.some( function (k) { return compareKeys_ (d , k ,keyName ) ; }); })); var newContent = self.getContent_(); if (oldContent.length != keys.length + newContent.length) { handleCode = enums.CODE.DRIVER_ASSERTION; handleError = 'after removing, length was ' + newContent.length + ' but should have been ' + oldContent.length - keys.length; } } catch(err) { handleError = cUseful.showError(err) + "(writing "+ self.getTableName()+" to memory)"; handleCode = enums.CODE.DRIVER; } return self.getParentHandler().makeResults (handleCode,handleError); }; |
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