insnlist.java

asm的源码包 并且包含英文的文档

            throw new IllegalArgumentException();
        }
        ++size;
        if (first == null) {
            first = insn;
            last = insn;
        } else {
            first.prev = insn;
            insn.next = first;
        }
        first = insn;
        cache = null;
        insn.index = 0; // insn now belongs to an InsnList
    }

    /**
     * Inserts the given instructions at the begining of this list.
     * 
     * @param insns an instruction list, which is cleared during the process.
     * @throws IllegalArgumentException if {@link #check} is <tt>true</tt>,
     *         and if insn == this.
     */
    public void insert(final InsnList insns) {
        if (check && insns == this) {
            throw new IllegalArgumentException();
        }
        if (insns.size == 0) {
            return;
        }
        size += insns.size;
        if (first == null) {
            first = insns.first;
            last = insns.last;
        } else {
            AbstractInsnNode elem = insns.last;
            first.prev = elem;
            elem.next = first;
            first = insns.first;
        }
        cache = null;
        insns.removeAll(false);
    }

    /**
     * Inserts the given instruction after the specified instruction.
     * 
     * @param location an instruction <i>of this list</i> after which insn must be
     *        inserted.
     * @param insn the instruction to be inserted, <i>which must not belong to
     *        any {@link InsnList}</i>.
     * @throws IllegalArgumentException if {@link #check} is <tt>true</tt>,
     *         and if i does not belong to this list or if insn belongs to an
     *         instruction list.
     */
    public void insert(final AbstractInsnNode location, final AbstractInsnNode insn) {
        if (check && !(contains(location) && insn.index == -1)) {
            throw new IllegalArgumentException();
        }
        ++size;
        AbstractInsnNode next = location.next;
        if (next == null) {
            last = insn;
        } else {
            next.prev = insn;
        }
        location.next = insn;
        insn.next = next;
        insn.prev = location;
        cache = null;
        insn.index = 0; // insn now belongs to an InsnList
    }

    /**
     * Inserts the given instructions after the specified instruction.
     * 
     * @param location an instruction <i>of this list</i> after which the instructions
     *        must be inserted.
     * @param insns the instruction list to be inserted, which is cleared during
     *        the process.
     * @throws IllegalArgumentException if {@link #check} is <tt>true</tt>,
     *         and if i does not belong to this list or if insns == this.
     */
    public void insert(final AbstractInsnNode location, final InsnList insns) {
        if (check && !(contains(location) && insns != this)) {
            throw new IllegalArgumentException();
        }
        if (insns.size == 0) {
            return;
        }
        size += insns.size;
        AbstractInsnNode ifirst = insns.first;
        AbstractInsnNode ilast = insns.last;
        AbstractInsnNode next = location.next;
        if (next == null) {
            last = ilast;
        } else {
            next.prev = ilast;
        }
        location.next = ifirst;
        ilast.next = next;
        ifirst.prev = location;
        cache = null;
        insns.removeAll(false);
    }
    
    /**
     * Inserts the given instruction before the specified instruction.
     * 
     * @param location an instruction <i>of this list</i> before which insn must be
     *        inserted.
     * @param insn the instruction to be inserted, <i>which must not belong to
     *        any {@link InsnList}</i>.
     * @throws IllegalArgumentException if {@link #check} is <tt>true</tt>,
     *         and if i does not belong to this list or if insn belongs to an
     *         instruction list.
     */
    public void insertBefore(final AbstractInsnNode location, final AbstractInsnNode insn) {
        if (check && !(contains(location) && insn.index == -1)) {
            throw new IllegalArgumentException();
        }
        ++size;
        AbstractInsnNode prev = location.prev;
        if (prev == null) {
            first = insn;
        } else {
            prev.next = insn;
        }
        location.prev = insn;
        insn.next = location;
        insn.prev = prev;
        cache = null;
        insn.index = 0; // insn now belongs to an InsnList
    }
    
    /**
     * Inserts the given instructions before the specified instruction.
     * 
     * @param location  an instruction <i>of this list</i> before which the instructions
     *        must be inserted.
     * @param insns the instruction list to be inserted, which is cleared during
     *        the process.
     * @throws IllegalArgumentException if {@link #check} is <tt>true</tt>,
     *         and if i does not belong to this list or if insns == this.
     */
    public void insertBefore(final AbstractInsnNode location, final InsnList insns) {
        if (check && !(contains(location ) && insns != this)) {
            throw new IllegalArgumentException();
        }
        if (insns.size == 0) {
            return;
        }
        size += insns.size;
        AbstractInsnNode ifirst = insns.first;
        AbstractInsnNode ilast = insns.last;
        AbstractInsnNode prev = location .prev;
        if (prev == null) {
            first = ifirst;
        } else {
            prev.next = ifirst;
        }
        location .prev = ilast;
        ilast.next = location ;
        ifirst.prev = prev;
        cache = null;
        insns.removeAll(false);
    }
    
    

    /**
     * Removes the given instruction from this list.
     * 
     * @param insn the instruction <i>of this list</i> that must be removed.
     * @throws IllegalArgumentException if {@link #check} is <tt>true</tt>,
     *         and if insn does not belong to this list.
     */
    public void remove(final AbstractInsnNode insn) {
        if (check && !contains(insn)) {
            throw new IllegalArgumentException();
        }
        --size;
        AbstractInsnNode next = insn.next;
        AbstractInsnNode prev = insn.prev;
        if (next == null) {
            if (prev == null) {
                first = null;
                last = null;
            } else {
                prev.next = null;
                last = prev;
            }
        } else {
            if (prev == null) {
                first = next;
                next.prev = null;
            } else {
                prev.next = next;
                next.prev = prev;
            }
        }
        cache = null;
        insn.index = -1; // insn no longer belongs to an InsnList
        insn.prev = null;
        insn.next = null;
    }

    /**
     * Removes all of the instructions of this list.
     * 
     * @param mark if the instructions must be marked as no longer belonging to
     *        any {@link InsnList}.
     */
    private void removeAll(final boolean mark) {
        if (mark) {
            AbstractInsnNode insn = first;
            while (insn != null) {
                AbstractInsnNode next = insn.next;
                insn.index = -1; // insn no longer belongs to an InsnList
                insn.prev = null;
                insn.next = null;
                insn = next;
            }
        }
        size = 0;
        first = null;
        last = null;
        cache = null;
    }

    /**
     * Removes all of the instructions of this list.
     */
    public void clear() {
        removeAll(check);
    }

    
    private final class InsnListIterator implements ListIterator {
        AbstractInsnNode next;
        AbstractInsnNode prev;

        public InsnListIterator(int index) {
            if(index==size()) {
                next = null;
                prev = getLast();
            } else {
                next = get(index);
                prev = next.prev;
            }
        }

        public boolean hasNext() {
            return next != null;
        }

        public Object next() {
            AbstractInsnNode result = next;
            prev = result;
            next = result.next;
            return result;
        }

        public void remove() {
            InsnList.this.remove(prev);
            prev = prev.prev;
        }

        public boolean hasPrevious() {
            return prev != null;
        }

        public Object previous() {
            AbstractInsnNode result = prev;
            next = result;
            prev = result.prev;
            return result;
        }

        public int nextIndex() {
            if (next == null) {
                return size();
            }
            if (cache == null) {
                cache = toArray();
            }
            return next.index;
        }

        public int previousIndex() {
            if (prev == null) {
                return -1;
            }
            if (cache == null) {
                cache = toArray();
            }
            return prev.index;
        }

        public void add(Object o) {
            InsnList.this.insertBefore(next, (AbstractInsnNode) o);
            prev = (AbstractInsnNode) o;
        }

        public void set(Object o) {
            InsnList.this.set(next.prev, (AbstractInsnNode) o);
            prev = (AbstractInsnNode) o;
        }
    }

}