hpack/src/main/java/com/twitter/hpack/DynamicTable.java
public void setCapacity(int capacity) {
    if (capacity < 0) {
      throw new IllegalArgumentException("Illegal Capacity: "+ capacity);
    }

    // initially capacity will be -1 so init won't return here
    if (this.capacity == capacity) {
      return;
    }
    this.capacity = capacity;

    if (capacity == 0) {
      clear();
    } else {
      // initially size will be 0 so remove won't be called
      while (size > capacity) {
        remove();
      }
    }

    int maxEntries = capacity / HEADER_ENTRY_OVERHEAD;
    if (capacity % HEADER_ENTRY_OVERHEAD != 0) {
      maxEntries++;
    }

    // check if capacity change requires us to reallocate the array
    if (headerFields != null && headerFields.length == maxEntries) {
      return;
    }

    HeaderField[] tmp = new HeaderField[maxEntries];

    // initially length will be 0 so there will be no copy
    int len = length();
    int cursor = tail;
    for (int i = 0; i < len; i++) {
      HeaderField entry = headerFields[cursor++];
      tmp[i] = entry;
      if (cursor == headerFields.length) {
        cursor = 0;
      }
    }

    this.tail = 0;
    this.head = tail + len;
    this.headerFields = tmp;
  }
public void setCapacity(int capacity) {
    if (capacity < 0) {
      throw new IllegalArgumentException("Illegal Capacity: "+ capacity);
    }

    // initially capacity will be -1 so init won't return here
    if (this.capacity == capacity) {
      return;
    }
    this.capacity = capacity;

    if (capacity == 0) {
      clear();
    } else {
      // initially size will be 0 so remove won't be called
      while (size > capacity) {
        remove();
      }
    }

    int maxEntries = capacity / HEADER_ENTRY_OVERHEAD;
    if (capacity % HEADER_ENTRY_OVERHEAD != 0) {
      maxEntries++;
    }

    // check if capacity change requires us to reallocate the array
    if (headerFields != null && headerFields.length == maxEntries) {
      return;
    }

    HeaderField[] tmp = new HeaderField[maxEntries];

    // initially length will be 0 so there will be no copy
    int len = length();
    int cursor = tail;
    for (int i = 0; i < len; i++) {
      HeaderField entry = headerFields[cursor++];
      tmp[i] = entry;
      if (cursor == headerFields.length) {
        cursor = 0;
      }
    }

    this.tail = 0;
    this.head = tail + len;
    this.headerFields = tmp;
  }
Set the maximum size of the dynamic table.
Entries are evicted from the dynamic table until the size of the table
is less than or equal to the maximum size.