Made 3500 SOQL Queries in one context. LIMITS HACK?

Question

Steps to reproduce:

1. Create Visualforce Email Template
2. Create Visualforce component and add it into the email template
3. Create Apex Controller for the component from pt.2
4. Do some SOQL queries there, process them and result pass into component markup.
5. Generate an email using Messaging.renderStoredEmailTemplate many times and get results from the email body. One email template generation takes 1 SOQL query limit, controller SOQL query limits are not counted.

LimitsHack.email

<messaging:emailTemplate subject="Limits Hack" recipientType="User" relatedToType="Contact">
    <messaging:plainTextEmailBody>
        <c:LimitsHackCmp/>
    </messaging:plainTextEmailBody>
</messaging:emailTemplate>

LimitsHackCmp.component

<apex:component id="LimitsHackCmp" controller="LimitsHackCmpController" access="global">
    {!results}
</apex:component>

LimitsHackCmpController.cls

    public String results {
        set;
        get {
            String result = '';
            for (Integer i = 0; i < 100; i++) {
                List<Account> accs = [SELECT Name FROM Account LIMIT 1 OFFSET :Math.mod(i, 3)];
                result += i + ') ' + accs[0].Name + ' ';
            }
            return result;
        }
    }
}

LimitsHackPlayground.cls

public with sharing class LimitsHackPlayground {
    public static void execute() {
        EmailTemplate emailTmpl = [
                SELECT Id
                FROM EmailTemplate
                WHERE DeveloperName = 'LimitsHack'
        ];

        System.debug(UserInfo.getUserId());

        for (Integer i = 0; i < 35; i++) {
            Long renderStart = System.now().getTime();
            String emailBody = Messaging.renderStoredEmailTemplate(emailTmpl.Id, UserInfo.getUserId(), '<any contact id>').plainTextBody;
            System.debug('LimitsHackPlayground: i=' + i + '. Took ' + (System.now().getTime() - renderStart) + ' ms. Email Body: ' + emailBody);
        }
    }
}

OFFSET :Math.mod(i, 3) I used to avoid any type of caching because of the deterministic repeatable query. Each email generation takes up to 500ms, so it is easy to get into the Apex CPU time limit. But still, I managed to make 35 email renders.

Question: Is it expected behavior or a bug? Did anybody meet similar behavior before?

Answer 1

Visualforce is a separate runtime, and it historically did not honor governor limits. If you're able to still run this code, make sure you log a bug. I logged a similar bug where I was able to create over 100MB of heap data used to insert 300,000 records at once, consuming approximately 9,000,000ms CPU time, and consuming several thousand times my actual storage limit (in a Developer Edition), all in a single transaction. They've fixed a lot of this based on my feedback, but this is one I've not yet reported.