localStorage Capacity

[Gondwana]

I tested the capacity of localStorage. It died after 524 keys of 10,000 chars each; ie, 5,240,000 chars (so about 10 MB assuming UTF16). That's enough for about 30 minutes of accelerometer data at 50 Hz. Presumably results would vary between companions.

function testStorage() {
  const maxKey = 1000
  localStorage.clear()
  let key=0
  let value=''
  let chars = '12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890'
  for (let i=0; i<50; i++) value += chars
  console.log(`len=${value.length} chars`);
  let timer = setInterval(() => {
    try {
      localStorage.setItem(key, value)
    } catch(e) {
      console.log(`setItem error: ${e.message} ${e.name}`);
      clearInterval(timer)
      return
    }
    console.log(`  set key ${key}`);
    key++
    if (key>=maxKey) {
      clearInterval(timer)
      console.log(`Done tesing; saved ${maxKey*value.length} chars`);
    }
  }, 1000);
}