Commit updated Javascript packages

build/javascript/node_modules/@videojs/http-streaming/src/util/gops.js

@@ -0,0 +1,119 @@
+import { ONE_SECOND_IN_TS } from 'mux.js/lib/utils/clock';
+
+/**
+ * Returns a list of gops in the buffer that have a pts value of 3 seconds or more in
+ * front of current time.
+ *
+ * @param {Array} buffer
+ *        The current buffer of gop information
+ * @param {number} currentTime
+ *        The current time
+ * @param {Double} mapping
+ *        Offset to map display time to stream presentation time
+ * @return {Array}
+ *         List of gops considered safe to append over
+ */
+export const gopsSafeToAlignWith = (buffer, currentTime, mapping) => {
+  if (typeof currentTime === 'undefined' || currentTime === null || !buffer.length) {
+    return [];
+  }
+
+  // pts value for current time + 3 seconds to give a bit more wiggle room
+  const currentTimePts = Math.ceil((currentTime - mapping + 3) * ONE_SECOND_IN_TS);
+
+  let i;
+
+  for (i = 0; i < buffer.length; i++) {
+    if (buffer[i].pts > currentTimePts) {
+      break;
+    }
+  }
+
+  return buffer.slice(i);
+};
+
+/**
+ * Appends gop information (timing and byteLength) received by the transmuxer for the
+ * gops appended in the last call to appendBuffer
+ *
+ * @param {Array} buffer
+ *        The current buffer of gop information
+ * @param {Array} gops
+ *        List of new gop information
+ * @param {boolean} replace
+ *        If true, replace the buffer with the new gop information. If false, append the
+ *        new gop information to the buffer in the right location of time.
+ * @return {Array}
+ *         Updated list of gop information
+ */
+export const updateGopBuffer = (buffer, gops, replace) => {
+  if (!gops.length) {
+    return buffer;
+  }
+
+  if (replace) {
+    // If we are in safe append mode, then completely overwrite the gop buffer
+    // with the most recent appeneded data. This will make sure that when appending
+    // future segments, we only try to align with gops that are both ahead of current
+    // time and in the last segment appended.
+    return gops.slice();
+  }
+
+  const start = gops[0].pts;
+
+  let i = 0;
+
+  for (i; i < buffer.length; i++) {
+    if (buffer[i].pts >= start) {
+      break;
+    }
+  }
+
+  return buffer.slice(0, i).concat(gops);
+};
+
+/**
+ * Removes gop information in buffer that overlaps with provided start and end
+ *
+ * @param {Array} buffer
+ *        The current buffer of gop information
+ * @param {Double} start
+ *        position to start the remove at
+ * @param {Double} end
+ *        position to end the remove at
+ * @param {Double} mapping
+ *        Offset to map display time to stream presentation time
+ */
+export const removeGopBuffer = (buffer, start, end, mapping) => {
+  const startPts = Math.ceil((start - mapping) * ONE_SECOND_IN_TS);
+  const endPts = Math.ceil((end - mapping) * ONE_SECOND_IN_TS);
+  const updatedBuffer = buffer.slice();
+
+  let i = buffer.length;
+
+  while (i--) {
+    if (buffer[i].pts <= endPts) {
+      break;
+    }
+  }
+
+  if (i === -1) {
+    // no removal because end of remove range is before start of buffer
+    return updatedBuffer;
+  }
+
+  let j = i + 1;
+
+  while (j--) {
+    if (buffer[j].pts <= startPts) {
+      break;
+    }
+  }
+
+  // clamp remove range start to 0 index
+  j = Math.max(j, 0);
+
+  updatedBuffer.splice(j, i - j + 1);
+
+  return updatedBuffer;
+};