Welcome!

Microsoft Cloud Authors: Pat Romanski, Srinivasan Sundara Rajan, Glenn Rossman, Janakiram MSV, Steven Mandel

Blog Feed Post

Improving .NET Application Performance Part 12: String Operations

In our previous article in this series we discussed Iteration and Looping. In this article we’ll focus on optimizing string operations.

The .NET Framework provides the System.String data type to represent a string. Intensive string manipulation can degrade performance. Every time you perform an operation to change string data, the original string in memory is discarded for later garbage collection and a new one is created to hold the new string data. Also note that the String type is a reference type, so the contents of the string are stored on the managed heap. As a result, strings must be garbage collected to be cleaned up.

This section summarizes recommendations you should consider when working with strings.

Avoid Inefficient String Concatenation

Excessive string concatenation results in many allocation and deallocation operations, because each time you perform an operation to change the string, a new one is created and the old one is subsequently collected by the garbage collector.

·         If you concatenate string literals, the compiler concatenates them at compile time.

//’Hello’ and ‘world’ are string literals

String str = “Hello” + “world”;

·         If you concatenate nonliteral strings, CLR concatenates them at run time. So using the + operator creates multiple strings objects in the managed heap.

·         Use StringBuilder for complex string manipulations and when you need to concatenate strings multiple times.

// using String and ‘+’ to append

String str = “Some Text”;

for ( … loop several times to build the string …) {

  str = str + ” additional text “;

}

// using String and .Append method to append

StringBuilder strBuilder = new StringBuilder(“Some Text “);

for ( … loop several times to build the string …) {

  strBuilder.Append(” additional text “);

}

Use + When the Number of Appends Is Known

If you know the number of appends to be made and you are concatenating the strings in one shot, prefer the + operator for concatenation.

String str = str1+str2+str3;

 

If you concatenate the strings in a single expression, only one call to String.Concat needs to be made. It results in no temporary strings (for partial combinations of the strings to be concatenated).

Avoid should not be using + on strings inside a loop or for multiple iterations. Use StringBuilder instead.

Use StringBuilder When the Number of Appends Is Unknown

If you do not know the number of appends to be made, which might be the case when iterating through a loop or building dynamic SQL queries, use the StringBuilder class as shown in the following code sample.

for (int i=0; i< Results.Count; i++)

{

  StringBuilder.Append (Results[i]);

}

 

The StringBuilder class starts with a default initial capacity of 16. Strings less than the initial capacity are stored in the StringBuilder object. The initial capacity of the buffer can be set by using the following overloaded constructor.

public StringBuilder (int capacity);

You can continue to concatenate without additional allocations until you consume the preallocated buffer. As a result, using a StringBuilder object is often more efficient than using String objects for concatenation. If you concatenate further, the StringBuilder class creates a new buffer of the size equal to double the current capacity.

So if you start with a StringBuilder of size 16 and exceed the limit, the StringBuilder allocates a new buffer of size 32 and copies the old string to the new buffer. The old buffer is inaccessible and becomes eligible for garbage collection.

You should try to set the initial capacity of the StringBuilder to an optimum value to reduce the cost of new allocations. To determine the optimum value for your case, the best way is to track the memory consumption by using the CLR profiler. For more information about how to use CLR profiler, see “How To: Use CLR Profiler” in the “How To” section of this guide.

Treat StringBuilder as an Accumulator

You can treat StringBuilder as an accumulator or reusable buffer. This helps avoid the allocations of temporary strings during multiple append iterations. Some of the scenarios where this helps are as follows:

  • Concatenating strings. You should always prefer the following approach to string concatenation when using StringBuilder.

StringBuilder sb;

sb.Append(str1);

sb.Append(str2);

Use the preceding code rather than the following.

sb.Append(str1+str2);

 

This is because you do not need to make the temporary str1+str2 to append str1 and then str2.

·         Concatenating the strings from various functions.

An example of this is shown in the following code sample.

StringBuilder sb;

sb.Append(f1());

sb.Append(f2());

sb.Append(f3());

The preceding code snippet results in temporary string allocations for the return values by the functions f1 (…), f2 (), f3 (). You can avoid these temporary allocations by using the following pattern.

void f1( sb,);

void f2( sb,);

void f3( sb,);

In this case, the StringBuilder instance is directly passed as an input parameter to the methods. sb.Append is directly called in the function body, which avoids the allocation of temporary strings.

Use the Overloaded Compare Method for Case-Insensitive String Comparisons

Carefully consider how you perform case-insensitive string comparisons. Avoid using ToLower as shown in the following code because you end up creating temporary string objects.

// Bad way for insensitive operations because ToLower creates temporary

strings

String str=”New York”;

String str2 = “New york”;

if (str.ToLower()==str2.ToLower())

  // do something

The more efficient way to perform case-insensitive string comparisons is to use the Compare method.

str.Compare(str,str2,false);

 

The String.Compare method uses the info in the CultureInfo.CompareInfo property to compare culture-sensitive strings.

Share Now:del.icio.usDiggFacebookLinkedInBlinkListDZoneGoogle BookmarksRedditStumbleUponTwitterRSS

Read the original blog entry...

More Stories By Hovhannes Avoyan

Hovhannes Avoyan is the CEO of PicsArt, Inc.,

@ThingsExpo Stories
Major trends and emerging technologies – from virtual reality and IoT, to Big Data and algorithms – are helping organizations innovate in the digital era. However, to create real business value, IT must think beyond the ‘what’ of digital transformation to the ‘how’ to harness emerging trends, innovation and disruption. Architecture is the key that underpins and ties all these efforts together. In the digital age, it’s important to invest in architecture, extend the enterprise footprint to the cl...
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
Fifty billion connected devices and still no winning protocols standards. HTTP, WebSockets, MQTT, and CoAP seem to be leading in the IoT protocol race at the moment but many more protocols are getting introduced on a regular basis. Each protocol has its pros and cons depending on the nature of the communications. Does there really need to be only one protocol to rule them all? Of course not. In his session at @ThingsExpo, Chris Matthieu, co-founder and CTO of Octoblu, walk you through how Oct...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life sett...
Fact is, enterprises have significant legacy voice infrastructure that’s costly to replace with pure IP solutions. How can we bring this analog infrastructure into our shiny new cloud applications? There are proven methods to bind both legacy voice applications and traditional PSTN audio into cloud-based applications and services at a carrier scale. Some of the most successful implementations leverage WebRTC, WebSockets, SIP and other open source technologies. In his session at @ThingsExpo, Da...
SYS-CON Events announced today that ReadyTalk, a leading provider of online conferencing and webinar services, has been named Vendor Presentation Sponsor at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. ReadyTalk delivers audio and web conferencing services that inspire collaboration and enable the Future of Work for today’s increasingly digital and mobile workforce. By combining intuitive, innovative tec...
Vidyo, Inc., has joined the Alliance for Open Media. The Alliance for Open Media is a non-profit organization working to define and develop media technologies that address the need for an open standard for video compression and delivery over the web. As a member of the Alliance, Vidyo will collaborate with industry leaders in pursuit of an open and royalty-free AOMedia Video codec, AV1. Vidyo’s contributions to the organization will bring to bear its long history of expertise in codec technolo...
SYS-CON Events announced today that Bsquare has been named “Silver Sponsor” of SYS-CON's @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. For more than two decades, Bsquare has helped its customers extract business value from a broad array of physical assets by making them intelligent, connecting them, and using the data they generate to optimize business processes.
If you’re responsible for an application that depends on the data or functionality of various IoT endpoints – either sensors or devices – your brand reputation depends on the security, reliability, and compliance of its many integrated parts. If your application fails to deliver the expected business results, your customers and partners won't care if that failure stems from the code you developed or from a component that you integrated. What can you do to ensure that the endpoints work as expect...
The Transparent Cloud-computing Consortium (abbreviation: T-Cloud Consortium) will conduct research activities into changes in the computing model as a result of collaboration between "device" and "cloud" and the creation of new value and markets through organic data processing High speed and high quality networks, and dramatic improvements in computer processing capabilities, have greatly changed the nature of applications and made the storing and processing of data on the network commonplace.
The vision of a connected smart home is becoming reality with the application of integrated wireless technologies in devices and appliances. The use of standardized and TCP/IP networked wireless technologies in line-powered and battery operated sensors and controls has led to the adoption of radios in the 2.4GHz band, including Wi-Fi, BT/BLE and 802.15.4 applied ZigBee and Thread. This is driving the need for robust wireless coexistence for multiple radios to ensure throughput performance and th...
Enterprise IT has been in the era of Hybrid Cloud for some time now. But it seems most conversations about Hybrid are focused on integrating AWS, Microsoft Azure, or Google ECM into existing on-premises systems. Where is all the Private Cloud? What do technology providers need to do to make their offerings more compelling? How should enterprise IT executives and buyers define their focus, needs, and roadmap, and communicate that clearly to the providers?
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management solutions, helping companies worldwide activate their data to drive more value and business insight and to transform moder...
The Internet of Things can drive efficiency for airlines and airports. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Sudip Majumder, senior director of development at Oracle, will discuss the technical details of the connected airline baggage and related social media solutions. These IoT applications will enhance travelers' journey experience and drive efficiency for the airlines and the airports. The session will include a working demo and a technical d...
There is little doubt that Big Data solutions will have an increasing role in the Enterprise IT mainstream over time. Big Data at Cloud Expo - to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA - has announced its Call for Papers is open. Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is...
Digital innovation is the next big wave of business transformation based on digital technologies of which IoT and Big Data are key components, For example: Business boundary innovation is a challenge to excavate third-party business value using IoT and BigData, like Nest Business structure innovation may propose re-building business structure from scratch, as Uber does in the taxicab industry The social model innovation is also a big challenge to the new social architecture with the design fr...
The many IoT deployments around the world are busy integrating smart devices and sensors into their enterprise IT infrastructures. Yet all of this technology – and there are an amazing number of choices – is of no use without the software to gather, communicate, and analyze the new data flows. Without software, there is no IT. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists will look at the protocols that communicate data and the emerging data analy...
DevOps at Cloud Expo, taking place Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long dev...
SYS-CON Events announced today that China Unicom will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. China United Network Communications Group Co. Ltd ("China Unicom") was officially established in 2009 on the basis of the merger of former China Netcom and former China Unicom. China Unicom mainly operates a full range of telecommunications services including mobile broadband (GSM, WCDMA, LTE F...
Data is an unusual currency; it is not restricted by the same transactional limitations as money or people. In fact, the more that you leverage your data across multiple business use cases, the more valuable it becomes to the organization. And the same can be said about the organization’s analytics. In his session at 19th Cloud Expo, Bill Schmarzo, CTO for the Big Data Practice at EMC, will introduce a methodology for capturing, enriching and sharing data (and analytics) across the organizati...