internal/metamorphic: write range keys

[jbowens]

Update the metamorphic tests to write range keys. This change does not yet add
reading of range keys to the metamorphic tests. Adding support for reading is
more complicated, broad change that will be added in a subsequent PR.

[cockroach-teamcity]

This change is 

[nicktrav]

Neat!

Reviewed 5 of 5 files at r1, 1 of 1 files at r2, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @itsbilal, @jbowens, and @sumeerbhola)

---

-- commits, line 5 at r1:
typo: s/is/is a/

---

internal/metamorphic/generator.go, line 925 at r1 (raw file):

}

func (g *generator) writerRangeKeyUnset() {

Wondering if we want some way of tracking intervals that have already been set, so that there's some increased probability of unsets hitting ranges that are already set. Same thing applies for dels tracking ranges that are already set / unset.

Perhaps a TODO, if you think it's useful / indicative of real workloads?

[sumeerbhola]

Reviewed 4 of 5 files at r1, 1 of 1 files at r2.
Reviewable status: all files reviewed, 4 unresolved discussions (waiting on @itsbilal and @jbowens)

---

internal/metamorphic/generator.go, line 173 at r2 (raw file):

}

func (g *generator) randSuffix(incMaxProb float64) []byte {

can you add a method comment.

---

internal/metamorphic/generator.go, line 897 at r2 (raw file):

	}

	start := g.randPrefixToWrite(0.001)

Can the following few lines be abstracted into a function that generates the [start, end) pair. Seems to be the same code repeated in 3 places.

[jbowens]

TFTRs!

Reviewable status: 4 of 5 files reviewed, 3 unresolved discussions (waiting on @itsbilal, @nicktrav, and @sumeerbhola)

---

internal/metamorphic/generator.go, line 925 at r1 (raw file):

Previously, nicktrav (Nick Travers) wrote…

Wondering if we want some way of tracking intervals that have already been set, so that there's some increased probability of unsets hitting ranges that are already set. Same thing applies for dels tracking ranges that are already set / unset.

Perhaps a TODO, if you think it's useful / indicative of real workloads?

Good call, added a TODO.

---

internal/metamorphic/generator.go, line 173 at r2 (raw file):

Previously, sumeerbhola wrote…

can you add a method comment.

Done.

---

internal/metamorphic/generator.go, line 897 at r2 (raw file):

Previously, sumeerbhola wrote…

Can the following few lines be abstracted into a function that generates the [start, end) pair. Seems to be the same code repeated in 3 places.

Done.

[sumeerbhola]

Reviewed 1 of 1 files at r3, all commit messages.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @itsbilal, @nicktrav, and @sumeerbhola)