Merge branch 'libarchive-upstream' into update-libarchive

Add Utilities/cmlibarchive using upstream libarchive 3.0.0-r3950
snapshot.

1 files changed, 709 insertions, 0 deletions

diff --git a/Utilities/cmlibarchive/libarchive/archive_write.c b/Utilities/cmlibarchive/libarchive/archive_write.c
new file mode 100644
index 0000000..c742d60
--- /dev/null
+++ b/Utilities/cmlibarchive/libarchive/archive_write.c
@@ -0,0 +1,709 @@
+/*-
+ * Copyright (c) 2003-2010 Tim Kientzle
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "archive_platform.h"
+__FBSDID("$FreeBSD: head/lib/libarchive/archive_write.c 201099 2009-12-28 03:03:00Z kientzle $");
+
+/*
+ * This file contains the "essential" portions of the write API, that
+ * is, stuff that will essentially always be used by any client that
+ * actually needs to write an archive.  Optional pieces have been, as
+ * far as possible, separated out into separate files to reduce
+ * needlessly bloating statically-linked clients.
+ */
+
+#ifdef HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#endif
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#endif
+#include <stdio.h>
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#include <time.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "archive.h"
+#include "archive_entry.h"
+#include "archive_private.h"
+#include "archive_write_private.h"
+
+static struct archive_vtable *archive_write_vtable(void);
+
+static int	_archive_filter_code(struct archive *, int);
+static const char *_archive_filter_name(struct archive *, int);
+static int64_t	_archive_filter_bytes(struct archive *, int);
+static int  _archive_write_filter_count(struct archive *);
+static int	_archive_write_close(struct archive *);
+static int	_archive_write_free(struct archive *);
+static int	_archive_write_header(struct archive *, struct archive_entry *);
+static int	_archive_write_finish_entry(struct archive *);
+static ssize_t	_archive_write_data(struct archive *, const void *, size_t);
+
+struct archive_none {
+	size_t buffer_size;
+	size_t avail;
+	char *buffer;
+	char *next;
+};
+
+static struct archive_vtable *
+archive_write_vtable(void)
+{
+	static struct archive_vtable av;
+	static int inited = 0;
+
+	if (!inited) {
+		av.archive_close = _archive_write_close;
+		av.archive_filter_bytes = _archive_filter_bytes;
+		av.archive_filter_code = _archive_filter_code;
+		av.archive_filter_name = _archive_filter_name;
+		av.archive_filter_count = _archive_write_filter_count;
+		av.archive_free = _archive_write_free;
+		av.archive_write_header = _archive_write_header;
+		av.archive_write_finish_entry = _archive_write_finish_entry;
+		av.archive_write_data = _archive_write_data;
+		inited = 1;
+	}
+	return (&av);
+}
+
+/*
+ * Allocate, initialize and return an archive object.
+ */
+struct archive *
+archive_write_new(void)
+{
+	struct archive_write *a;
+	unsigned char *nulls;
+
+	a = (struct archive_write *)malloc(sizeof(*a));
+	if (a == NULL)
+		return (NULL);
+	memset(a, 0, sizeof(*a));
+	a->archive.magic = ARCHIVE_WRITE_MAGIC;
+	a->archive.state = ARCHIVE_STATE_NEW;
+	a->archive.vtable = archive_write_vtable();
+	/*
+	 * The value 10240 here matches the traditional tar default,
+	 * but is otherwise arbitrary.
+	 * TODO: Set the default block size from the format selected.
+	 */
+	a->bytes_per_block = 10240;
+	a->bytes_in_last_block = -1;	/* Default */
+
+	/* Initialize a block of nulls for padding purposes. */
+	a->null_length = 1024;
+	nulls = (unsigned char *)malloc(a->null_length);
+	if (nulls == NULL) {
+		free(a);
+		return (NULL);
+	}
+	memset(nulls, 0, a->null_length);
+	a->nulls = nulls;
+	return (&a->archive);
+}
+
+/*
+ * Set the block size.  Returns 0 if successful.
+ */
+int
+archive_write_set_bytes_per_block(struct archive *_a, int bytes_per_block)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_NEW, "archive_write_set_bytes_per_block");
+	a->bytes_per_block = bytes_per_block;
+	return (ARCHIVE_OK);
+}
+
+/*
+ * Get the current block size.  -1 if it has never been set.
+ */
+int
+archive_write_get_bytes_per_block(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_ANY, "archive_write_get_bytes_per_block");
+	return (a->bytes_per_block);
+}
+
+/*
+ * Set the size for the last block.
+ * Returns 0 if successful.
+ */
+int
+archive_write_set_bytes_in_last_block(struct archive *_a, int bytes)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_ANY, "archive_write_set_bytes_in_last_block");
+	a->bytes_in_last_block = bytes;
+	return (ARCHIVE_OK);
+}
+
+/*
+ * Return the value set above.  -1 indicates it has not been set.
+ */
+int
+archive_write_get_bytes_in_last_block(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_ANY, "archive_write_get_bytes_in_last_block");
+	return (a->bytes_in_last_block);
+}
+
+/*
+ * dev/ino of a file to be rejected.  Used to prevent adding
+ * an archive to itself recursively.
+ */
+int
+archive_write_set_skip_file(struct archive *_a, int64_t d, int64_t i)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_ANY, "archive_write_set_skip_file");
+	a->skip_file_set = 1;
+	a->skip_file_dev = d;
+	a->skip_file_ino = i;
+	return (ARCHIVE_OK);
+}
+
+/*
+ * Allocate and return the next filter structure.
+ */
+struct archive_write_filter *
+__archive_write_allocate_filter(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	struct archive_write_filter *f;
+
+	f = calloc(1, sizeof(*f));
+	f->archive = _a;
+	if (a->filter_first == NULL)
+		a->filter_first = f;
+	else
+		a->filter_last->next_filter = f;
+	a->filter_last = f;
+	return f;
+}
+
+/*
+ * Write data to a particular filter.
+ */
+int
+__archive_write_filter(struct archive_write_filter *f,
+    const void *buff, size_t length)
+{
+	int r;
+	if (length == 0)
+		return(ARCHIVE_OK);
+	r = (f->write)(f, buff, length);
+	f->bytes_written += length;
+	return (r);
+}
+
+/*
+ * Open a filter.
+ */
+int
+__archive_write_open_filter(struct archive_write_filter *f)
+{
+	if (f->open == NULL)
+		return (ARCHIVE_OK);
+	return (f->open)(f);
+}
+
+/*
+ * Close a filter.
+ */
+int
+__archive_write_close_filter(struct archive_write_filter *f)
+{
+	if (f->close != NULL)
+		return (f->close)(f);
+	if (f->next_filter != NULL)
+		return (__archive_write_close_filter(f->next_filter));
+	return (ARCHIVE_OK);
+}
+
+int
+__archive_write_output(struct archive_write *a, const void *buff, size_t length)
+{
+	return (__archive_write_filter(a->filter_first, buff, length));
+}
+
+int
+__archive_write_nulls(struct archive_write *a, size_t length)
+{
+	if (length == 0)
+		return (ARCHIVE_OK);
+
+	while (length > 0) {
+		size_t to_write = length < a->null_length ? length : a->null_length;
+		int r = __archive_write_output(a, a->nulls, to_write);
+		if (r < ARCHIVE_OK)
+			return (r);
+		length -= to_write;
+	}
+	return (ARCHIVE_OK);
+}
+
+static int
+archive_write_client_open(struct archive_write_filter *f)
+{
+	struct archive_write *a = (struct archive_write *)f->archive;
+	struct archive_none *state;
+	void *buffer;
+	size_t buffer_size;
+
+	f->bytes_per_block = archive_write_get_bytes_per_block(f->archive);
+	f->bytes_in_last_block =
+	    archive_write_get_bytes_in_last_block(f->archive);
+	buffer_size = f->bytes_per_block;
+
+	state = (struct archive_none *)calloc(1, sizeof(*state));
+	buffer = (char *)malloc(buffer_size);
+	if (state == NULL || buffer == NULL) {
+		free(state);
+		free(buffer);
+		archive_set_error(f->archive, ENOMEM,
+		    "Can't allocate data for output buffering");
+		return (ARCHIVE_FATAL);
+	}
+
+	state->buffer_size = buffer_size;
+	state->buffer = buffer;
+	state->next = state->buffer;
+	state->avail = state->buffer_size;
+	f->data = state;
+
+	if (a->client_opener == NULL)
+		return (ARCHIVE_OK);
+	return (a->client_opener(f->archive, a->client_data));
+}
+
+static int
+archive_write_client_write(struct archive_write_filter *f,
+    const void *_buff, size_t length)
+{
+	struct archive_write *a = (struct archive_write *)f->archive;
+        struct archive_none *state = (struct archive_none *)f->data;
+        const char *buff = (const char *)_buff;
+        ssize_t remaining, to_copy;
+        ssize_t bytes_written;
+
+        remaining = length;
+
+        /*
+         * If there is no buffer for blocking, just pass the data
+         * straight through to the client write callback.  In
+         * particular, this supports "no write delay" operation for
+         * special applications.  Just set the block size to zero.
+         */
+        if (state->buffer_size == 0) {
+                while (remaining > 0) {
+                        bytes_written = (a->client_writer)(&a->archive,
+                            a->client_data, buff, remaining);
+                        if (bytes_written <= 0)
+                                return (ARCHIVE_FATAL);
+                        remaining -= bytes_written;
+                        buff += bytes_written;
+                }
+                return (ARCHIVE_OK);
+        }
+
+        /* If the copy buffer isn't empty, try to fill it. */
+        if (state->avail < state->buffer_size) {
+                /* If buffer is not empty... */
+                /* ... copy data into buffer ... */
+                to_copy = ((size_t)remaining > state->avail) ?
+			state->avail : (size_t)remaining;
+                memcpy(state->next, buff, to_copy);
+                state->next += to_copy;
+                state->avail -= to_copy;
+                buff += to_copy;
+                remaining -= to_copy;
+                /* ... if it's full, write it out. */
+                if (state->avail == 0) {
+			char *p = state->buffer;
+			size_t to_write = state->buffer_size;
+			while (to_write > 0) {
+				bytes_written = (a->client_writer)(&a->archive,
+				    a->client_data, p, to_write);
+				if (bytes_written <= 0)
+					return (ARCHIVE_FATAL);
+				if ((size_t)bytes_written > to_write) {
+					archive_set_error(&(a->archive),
+					    -1, "write overrun");
+					return (ARCHIVE_FATAL);
+				}
+				p += bytes_written;
+				to_write -= bytes_written;
+			}
+                        state->next = state->buffer;
+                        state->avail = state->buffer_size;
+                }
+        }
+
+        while ((size_t)remaining > state->buffer_size) {
+                /* Write out full blocks directly to client. */
+                bytes_written = (a->client_writer)(&a->archive,
+                    a->client_data, buff, state->buffer_size);
+                if (bytes_written <= 0)
+                        return (ARCHIVE_FATAL);
+                buff += bytes_written;
+                remaining -= bytes_written;
+        }
+
+        if (remaining > 0) {
+                /* Copy last bit into copy buffer. */
+                memcpy(state->next, buff, remaining);
+                state->next += remaining;
+                state->avail -= remaining;
+        }
+        return (ARCHIVE_OK);
+}
+
+static int
+archive_write_client_close(struct archive_write_filter *f)
+{
+	struct archive_write *a = (struct archive_write *)f->archive;
+        struct archive_none *state = (struct archive_none *)f->data;
+        ssize_t block_length;
+        ssize_t target_block_length;
+        ssize_t bytes_written;
+        int ret = ARCHIVE_OK;
+
+        /* If there's pending data, pad and write the last block */
+        if (state->next != state->buffer) {
+                block_length = state->buffer_size - state->avail;
+
+                /* Tricky calculation to determine size of last block */
+                if (a->bytes_in_last_block <= 0)
+                        /* Default or Zero: pad to full block */
+                        target_block_length = a->bytes_per_block;
+                else
+                        /* Round to next multiple of bytes_in_last_block. */
+                        target_block_length = a->bytes_in_last_block *
+                            ( (block_length + a->bytes_in_last_block - 1) /
+                                a->bytes_in_last_block);
+                if (target_block_length > a->bytes_per_block)
+                        target_block_length = a->bytes_per_block;
+                if (block_length < target_block_length) {
+                        memset(state->next, 0,
+                            target_block_length - block_length);
+                        block_length = target_block_length;
+                }
+                bytes_written = (a->client_writer)(&a->archive,
+                    a->client_data, state->buffer, block_length);
+                ret = bytes_written <= 0 ? ARCHIVE_FATAL : ARCHIVE_OK;
+        }
+	if (a->client_closer)
+		(*a->client_closer)(&a->archive, a->client_data);
+	free(state->buffer);
+        free(state);
+        a->client_data = NULL;
+        return (ret);
+}
+
+/*
+ * Open the archive using the current settings.
+ */
+int
+archive_write_open(struct archive *_a, void *client_data,
+    archive_open_callback *opener, archive_write_callback *writer,
+    archive_close_callback *closer)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	struct archive_write_filter *client_filter;
+	int ret, r1;
+
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_NEW, "archive_write_open");
+	archive_clear_error(&a->archive);
+
+	a->client_writer = writer;
+	a->client_opener = opener;
+	a->client_closer = closer;
+	a->client_data = client_data;
+
+	client_filter = __archive_write_allocate_filter(_a);
+	client_filter->open = archive_write_client_open;
+	client_filter->write = archive_write_client_write;
+	client_filter->close = archive_write_client_close;
+
+	ret = __archive_write_open_filter(a->filter_first);
+	if (ret < ARCHIVE_WARN) {
+		r1 = __archive_write_close_filter(a->filter_first);
+		return (r1 < ret ? r1 : ret);
+	}
+
+	a->archive.state = ARCHIVE_STATE_HEADER;
+	if (a->format_init)
+		ret = (a->format_init)(a);
+	return (ret);
+}
+
+/*
+ * Close out the archive.
+ */
+static int
+_archive_write_close(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	int r = ARCHIVE_OK, r1 = ARCHIVE_OK;
+
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_ANY | ARCHIVE_STATE_FATAL,
+	    "archive_write_close");
+	if (a->archive.state == ARCHIVE_STATE_NEW
+	    || a->archive.state == ARCHIVE_STATE_CLOSED)
+		return (ARCHIVE_OK); /* Okay to close() when not open. */
+
+	archive_clear_error(&a->archive);
+
+	/* Finish the last entry. */
+	if (a->archive.state == ARCHIVE_STATE_DATA)
+		r = ((a->format_finish_entry)(a));
+
+	/* Finish off the archive. */
+	/* TODO: have format closers invoke compression close. */
+	if (a->format_close != NULL) {
+		r1 = (a->format_close)(a);
+		if (r1 < r)
+			r = r1;
+	}
+
+	/* Finish the compression and close the stream. */
+	r1 = __archive_write_close_filter(a->filter_first);
+	if (r1 < r)
+		r = r1;
+
+	if (a->archive.state != ARCHIVE_STATE_FATAL)
+		a->archive.state = ARCHIVE_STATE_CLOSED;
+	return (r);
+}
+
+static int
+_archive_write_filter_count(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	struct archive_write_filter *p = a->filter_first;
+	int count = 0;
+	while(p) {
+		count++;
+		p = p->next_filter;
+	}
+	return count;
+}
+
+void
+__archive_write_filters_free(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	int r = ARCHIVE_OK, r1;
+
+	while (a->filter_first != NULL) {
+		struct archive_write_filter *next
+		    = a->filter_first->next_filter;
+		if (a->filter_first->free != NULL) {
+			r1 = (*a->filter_first->free)(a->filter_first);
+			if (r > r1)
+				r = r1;
+		}
+		free(a->filter_first);
+		a->filter_first = next;
+	}
+	a->filter_last = NULL;
+}
+
+/*
+ * Destroy the archive structure.
+ *
+ * Be careful: user might just call write_new and then write_free.
+ * Don't assume we actually wrote anything or performed any non-trivial
+ * initialization.
+ */
+static int
+_archive_write_free(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	int r = ARCHIVE_OK, r1;
+
+	if (_a == NULL)
+		return (ARCHIVE_OK);
+	/* It is okay to call free() in state FATAL. */
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_ANY | ARCHIVE_STATE_FATAL, "archive_write_free");
+	if (a->archive.state != ARCHIVE_STATE_FATAL)
+		r = archive_write_close(&a->archive);
+
+	/* Release format resources. */
+	if (a->format_free != NULL) {
+		r1 = (a->format_free)(a);
+		if (r1 < r)
+			r = r1;
+	}
+
+	__archive_write_filters_free(_a);
+
+	/* Release various dynamic buffers. */
+	free((void *)(uintptr_t)(const void *)a->nulls);
+	archive_string_free(&a->archive.error_string);
+	a->archive.magic = 0;
+	__archive_clean(&a->archive);
+	free(a);
+	return (r);
+}
+
+/*
+ * Write the appropriate header.
+ */
+static int
+_archive_write_header(struct archive *_a, struct archive_entry *entry)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	int ret, r2;
+
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_DATA | ARCHIVE_STATE_HEADER, "archive_write_header");
+	archive_clear_error(&a->archive);
+
+	if (a->format_write_header == NULL) {
+		archive_set_error(&(a->archive), -1,
+		    "Format must be set before you can write to an archive.");
+		a->archive.state = ARCHIVE_STATE_FATAL;
+		return (ARCHIVE_FATAL);
+	}
+
+	/* In particular, "retry" and "fatal" get returned immediately. */
+	ret = archive_write_finish_entry(&a->archive);
+	if (ret == ARCHIVE_FATAL) {
+		a->archive.state = ARCHIVE_STATE_FATAL;
+		return (ARCHIVE_FATAL);
+	}
+	if (ret < ARCHIVE_OK && ret != ARCHIVE_WARN)
+		return (ret);
+
+	if (a->skip_file_set &&
+	    archive_entry_dev_is_set(entry) &&
+	    archive_entry_ino_is_set(entry) &&
+	    archive_entry_dev(entry) == a->skip_file_dev &&
+	    archive_entry_ino64(entry) == a->skip_file_ino) {
+		archive_set_error(&a->archive, 0,
+		    "Can't add archive to itself");
+		return (ARCHIVE_FAILED);
+	}
+
+	/* Format and write header. */
+	r2 = ((a->format_write_header)(a, entry));
+	if (r2 == ARCHIVE_FATAL) {
+		a->archive.state = ARCHIVE_STATE_FATAL;
+		return (ARCHIVE_FATAL);
+	}
+	if (r2 < ret)
+		ret = r2;
+
+	a->archive.state = ARCHIVE_STATE_DATA;
+	return (ret);
+}
+
+static int
+_archive_write_finish_entry(struct archive *_a)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	int ret = ARCHIVE_OK;
+
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA,
+	    "archive_write_finish_entry");
+	if (a->archive.state & ARCHIVE_STATE_DATA)
+		ret = (a->format_finish_entry)(a);
+	a->archive.state = ARCHIVE_STATE_HEADER;
+	return (ret);
+}
+
+/*
+ * Note that the compressor is responsible for blocking.
+ */
+static ssize_t
+_archive_write_data(struct archive *_a, const void *buff, size_t s)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
+	    ARCHIVE_STATE_DATA, "archive_write_data");
+	archive_clear_error(&a->archive);
+	return ((a->format_write_data)(a, buff, s));
+}
+
+static struct archive_write_filter *
+filter_lookup(struct archive *_a, int n)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	struct archive_write_filter *f = a->filter_first;
+	if (n == -1)
+		return a->filter_last;
+	if (n < 0)
+		return NULL;
+	while (n > 0 && f != NULL) {
+		f = f->next_filter;
+		--n;
+	}
+	return f;
+}
+
+static int
+_archive_filter_code(struct archive *_a, int n)
+{
+	struct archive_write_filter *f = filter_lookup(_a, n);
+	return f == NULL ? -1 : f->code;
+}
+
+static const char *
+_archive_filter_name(struct archive *_a, int n)
+{
+	struct archive_write_filter *f = filter_lookup(_a, n);
+	return f == NULL ? NULL : f->name;
+}
+
+static int64_t
+_archive_filter_bytes(struct archive *_a, int n)
+{
+	struct archive_write_filter *f = filter_lookup(_a, n);
+	return f == NULL ? -1 : f->bytes_written;
+}