Partition

Each pixel represents approximately one byte.

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.node rect {
  fill: #ddd;
}

.node text {
  font: 10px sans-serif;
}

.node tspan:last-child {
  font-size: 9px;
  fill-opacity: 0.8;
}

.node--internal text {
  font-weight: bold;
}

.node--leaf rect {
  fill-opacity: 0.6;
}

</style>
<svg width="960" height="4980"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>

var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");

var format = d3.format(",d");

var color = d3.scaleOrdinal(d3.schemeCategory10);

var stratify = d3.stratify()
    .parentId(function(d) { return d.id.substring(0, d.id.lastIndexOf(".")); });

var partition = d3.partition()
    .size([height, width])
    .padding(1)
    .round(true);

d3.csv("flare.csv", function(error, data) {
  if (error) throw error;

var root = stratify(data)
      .sum(function(d) { return d.value; })
      .sort(function(a, b) { return b.height - a.height || b.value - a.value; });

partition(root);

var cell = svg
    .selectAll(".node")
    .data(root.descendants())
    .enter().append("g")
      .attr("class", function(d) { return "node" + (d.children ? " node--internal" : " node--leaf"); })
      .attr("transform", function(d) { return "translate(" + d.y0 + "," + d.x0 + ")"; });

cell.append("rect")
      .attr("id", function(d) { return "rect-" + d.id; })
      .attr("width", function(d) { return d.y1 - d.y0; })
      .attr("height", function(d) { return d.x1 - d.x0; })
    .filter(function(d) { return !d.children; })
      .style("fill", function(d) { while (d.depth > 1) d = d.parent; return color(d.id); });

cell.append("clipPath")
      .attr("id", function(d) { return "clip-" + d.id; })
    .append("use")
      .attr("xlink:href", function(d) { return "#rect-" + d.id + ""; });

cell.append("text")
      .attr("clip-path", function(d) { return "url(#clip-" + d.id + ")"; })
      .attr("x", 4)
    .selectAll("tspan")
      .data(function(d) { return [d.id.substring(d.id.lastIndexOf(".") + 1), " " + format(d.value)]; })
    .enter().append("tspan")
      .attr("y", 13)
      .text(function(d) { return d; });

cell.append("title")
      .text(function(d) { return d.id + "\n" + format(d.value); });
});

</script>

https://d3js.org/d3.v4.min.js