Use text inside svg will cause memory leak

In a scene, I encountered this problem when I used SVG to synthesize text onto an image.

This is a simplified code:

const sharp = require('sharp');

let count = 0;
setInterval(() => {
    if (++count % 100 === 0) {
        console.log(count, process.memoryUsage());
    }

    sharp(Buffer.from(`
        <svg>
            <text>example</text>
        </svg>
    `)).toBuffer();
}, 100);

After 500, 1000, 2000 times：

500 { rss: 343126016,
  heapTotal: 9256960,
  heapUsed: 7043760,
  external: 44416 }

1000 { rss: 641712128,
  heapTotal: 11354112,
  heapUsed: 8856440,
  external: 95232 }

2000 { rss: 1231851520,
  heapTotal: 12402688,
  heapUsed: 10316248,
  external: 125248 }

I guess the underlying code is causing this problem, but I’m not sure, so give you a feedback.

[shasharoman]

I made a big mistake because my production environment is linux, and after a failure I used my own OS X (10.11.6) to locate and debug, and then guessed that using svg+text caused a memory leak.

After reading your last reply, I continued to run “simplified code” on OS X. This time I ran 8000 times and the RSS size was about 4.8G, but this may be because my machine’s available memory is too large.

After that I went to the linux environment to run this code, the RSS size is always at 30M-40M, which forced me to think about the whole problem. I then used a complete local environment to test my application, making sure it should be an RSS issue. The last application crash was an exception caused by a shortage of system memory.

After confirming that it is not a memory leak, I should focus on how to optimize RSS. I think the OS X memory leak probability is low and will not be used as a production environment, so this issue should be closed. If you are interested, you can also run “Simplified Code” in the OS X environment.

Thank you very much for providing such a good tool library.

[lovell]

I’m unable to reproduce this with the latest version of sharp on Linux using the “simplified code” of the first comment.

100 { rss: 47820800,
  heapTotal: 8208384,
  heapUsed: 5804256,
  external: 16960 }
500 { rss: 48328704,
  heapTotal: 8732672,
  heapUsed: 6690656,
  external: 36384 }
1000 { rss: 47693824,
  heapTotal: 8732672,
  heapUsed: 5918232,
  external: 25344 }

Which platform and versions are you using?