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Diffstat (limited to 'libnautilus-private/nautilus-annotation.c')
| -rw-r--r-- | libnautilus-private/nautilus-annotation.c | 708 |
1 files changed, 708 insertions, 0 deletions
diff --git a/libnautilus-private/nautilus-annotation.c b/libnautilus-private/nautilus-annotation.c new file mode 100644 index 000000000..287ed0886 --- /dev/null +++ b/libnautilus-private/nautilus-annotation.c @@ -0,0 +1,708 @@ +/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- + + nautilus-annotation.c: routines for getting and setting xml-based annotations associated + with the digest of a file. + + Copyright (C) 1999, 2000 Eazel, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public + License along with this program; if not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. + + Author: Andy Hertzfeld <andy@eazel.com> +*/ + +/* + * This code implements the MD5 message-digest algorithm. + * The algorithm is due to Ron Rivest. This code was + * written by Colin Plumb in 1993, no copyright is claimed. + * This code is in the public domain; do with it what you wish. + * + * Equivalent code is available from RSA Data Security, Inc. + * This code has been tested against that, and is equivalent, + * except that you don't need to include two pages of legalese + * with every copy. + * + * To compute the message digest of a chunk of bytes, declare an + * MD5Context structure, pass it to md5_init, call md5_update as + * needed on buffers full of bytes, and then call md5_Final, which + * will fill a supplied 16-byte array with the digest. + */ + +/* parts of this file are : + * Written March 1993 by Branko Lankester + * Modified June 1993 by Colin Plumb for altered md5.c. + * Modified October 1995 by Erik Troan for RPM + */ + +#include <config.h> +#include "nautilus-annotation.h" + +#include "nautilus-file-utilities.h" +#include "nautilus-file.h" +#include "nautilus-file-private.h" +#include "nautilus-global-preferences.h" +#include "nautilus-metadata.h" +#include "nautilus-preferences.h" +#include "nautilus-string.h" +#include "nautilus-xml-extensions.h" +#include <gnome-xml/parser.h> +#include <gnome-xml/xmlmemory.h> +#include <libgnome/gnome-util.h> +#include <libgnomevfs/gnome-vfs.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +/* icon selection callback function. */ +typedef void (* NautilusCalculateDigestCallback) (NautilusFile *file, char *file_digest); +typedef struct NautilusDigestFileHandle NautilusDigestFileHandle; + +typedef struct { + guint32 buf[4]; + guint32 bits[2]; + guchar in[64]; + int doByteReverse; +} MD5Context ; + +struct NautilusDigestFileHandle { + GnomeVFSAsyncHandle *handle; + NautilusCalculateDigestCallback callback; + NautilusFile *file; + char *buffer; + MD5Context digest_context; +}; + +#define READ_CHUNK_SIZE 65536 +#define SERVER_URI_TEMPLATE "http://dellbert.differnet.com/get_notes.cgi?ids=%s" + + +static GList* annotation_request_queue = NULL; + +static void md5_transform (guint32 buf[4], const guint32 in[16]); + +static int _ie = 0x44332211; +static union _endian { int i; char b[4]; } *_endian = (union _endian *)&_ie; +#define IS_BIG_ENDIAN() (_endian->b[0] == '\x44') +#define IS_LITTLE_ENDIAN() (_endian->b[0] == '\x11') + + +/* + * Note: this code is harmless on little-endian machines. + */ +static void +_byte_reverse (guchar *buf, guint32 longs) +{ + guint32 t; + do { + t = (guint32) ((guint32) buf[3] << 8 | buf[2]) << 16 | + ((guint32) buf[1] << 8 | buf[0]); + *(guint32 *) buf = t; + buf += 4; + } while (--longs); +} + +/** + * md5_init: Initialise an md5 context object + * @ctx: md5 context + * + * Initialise an md5 buffer. + * + **/ +static void +md5_init (MD5Context *ctx) +{ + ctx->buf[0] = 0x67452301; + ctx->buf[1] = 0xefcdab89; + ctx->buf[2] = 0x98badcfe; + ctx->buf[3] = 0x10325476; + + ctx->bits[0] = 0; + ctx->bits[1] = 0; + + if (IS_BIG_ENDIAN()) + ctx->doByteReverse = 1; + else + ctx->doByteReverse = 0; +} + + + +/** + * md5_update: add a buffer to md5 hash computation + * @ctx: conetxt object used for md5 computaion + * @buf: buffer to add + * @len: buffer length + * + * Update context to reflect the concatenation of another buffer full + * of bytes. Use this to progressively construct an md5 hash. + **/ +static void +md5_update (MD5Context *ctx, const guchar *buf, guint32 len) +{ + guint32 t; + + /* Update bitcount */ + + t = ctx->bits[0]; + if ((ctx->bits[0] = t + ((guint32) len << 3)) < t) + ctx->bits[1]++; /* Carry from low to high */ + ctx->bits[1] += len >> 29; + + t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */ + + /* Handle any leading odd-sized chunks */ + + if (t) { + guchar *p = (guchar *) ctx->in + t; + + t = 64 - t; + if (len < t) { + memcpy (p, buf, len); + return; + } + memcpy (p, buf, t); + if (ctx->doByteReverse) + _byte_reverse (ctx->in, 16); + md5_transform (ctx->buf, (guint32 *) ctx->in); + buf += t; + len -= t; + } + /* Process data in 64-byte chunks */ + + while (len >= 64) { + memcpy (ctx->in, buf, 64); + if (ctx->doByteReverse) + _byte_reverse (ctx->in, 16); + md5_transform (ctx->buf, (guint32 *) ctx->in); + buf += 64; + len -= 64; + } + + /* Handle any remaining bytes of data. */ + + memcpy (ctx->in, buf, len); +} + + + + + +/* + * Final wrapup - pad to 64-byte boundary with the bit pattern + * 1 0* (64-bit count of bits processed, MSB-first) + */ +/** + * md5_final: copy the final md5 hash to a bufer + * @digest: 16 bytes buffer + * @ctx: context containing the calculated md5 + * + * copy the final md5 hash to a bufer + **/ +static void +md5_final (MD5Context *ctx, guchar digest[16]) +{ + guint32 count; + guchar *p; + + /* Compute number of bytes mod 64 */ + count = (ctx->bits[0] >> 3) & 0x3F; + + /* Set the first char of padding to 0x80. This is safe since there is + always at least one byte free */ + p = ctx->in + count; + *p++ = 0x80; + + /* Bytes of padding needed to make 64 bytes */ + count = 64 - 1 - count; + + /* Pad out to 56 mod 64 */ + if (count < 8) { + /* Two lots of padding: Pad the first block to 64 bytes */ + memset (p, 0, count); + if (ctx->doByteReverse) + _byte_reverse (ctx->in, 16); + md5_transform (ctx->buf, (guint32 *) ctx->in); + + /* Now fill the next block with 56 bytes */ + memset (ctx->in, 0, 56); + } else { + /* Pad block to 56 bytes */ + memset (p, 0, count - 8); + } + if (ctx->doByteReverse) + _byte_reverse (ctx->in, 14); + + /* Append length in bits and transform */ + ((guint32 *) ctx->in)[14] = ctx->bits[0]; + ((guint32 *) ctx->in)[15] = ctx->bits[1]; + + md5_transform (ctx->buf, (guint32 *) ctx->in); + if (ctx->doByteReverse) + _byte_reverse ((guchar *) ctx->buf, 4); + memcpy (digest, ctx->buf, 16); +} + + + + +/* The four core functions - F1 is optimized somewhat */ + +/* #define F1(x, y, z) (x & y | ~x & z) */ +#define F1(x, y, z) (z ^ (x & (y ^ z))) +#define F2(x, y, z) F1(z, x, y) +#define F3(x, y, z) (x ^ y ^ z) +#define F4(x, y, z) (y ^ (x | ~z)) + +/* This is the central step in the MD5 algorithm. */ +#define MD5STEP(f, w, x, y, z, data, s) \ + ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x ) + +/* + * The core of the MD5 algorithm, this alters an existing MD5 hash to + * reflect the addition of 16 longwords of new data. md5_Update blocks + * the data and converts bytes into longwords for this routine. + */ +static void +md5_transform (guint32 buf[4], const guint32 in[16]) +{ + register guint32 a, b, c, d; + + a = buf[0]; + b = buf[1]; + c = buf[2]; + d = buf[3]; + + MD5STEP (F1, a, b, c, d, in[0] + 0xd76aa478, 7); + MD5STEP (F1, d, a, b, c, in[1] + 0xe8c7b756, 12); + MD5STEP (F1, c, d, a, b, in[2] + 0x242070db, 17); + MD5STEP (F1, b, c, d, a, in[3] + 0xc1bdceee, 22); + MD5STEP (F1, a, b, c, d, in[4] + 0xf57c0faf, 7); + MD5STEP (F1, d, a, b, c, in[5] + 0x4787c62a, 12); + MD5STEP (F1, c, d, a, b, in[6] + 0xa8304613, 17); + MD5STEP (F1, b, c, d, a, in[7] + 0xfd469501, 22); + MD5STEP (F1, a, b, c, d, in[8] + 0x698098d8, 7); + MD5STEP (F1, d, a, b, c, in[9] + 0x8b44f7af, 12); + MD5STEP (F1, c, d, a, b, in[10] + 0xffff5bb1, 17); + MD5STEP (F1, b, c, d, a, in[11] + 0x895cd7be, 22); + MD5STEP (F1, a, b, c, d, in[12] + 0x6b901122, 7); + MD5STEP (F1, d, a, b, c, in[13] + 0xfd987193, 12); + MD5STEP (F1, c, d, a, b, in[14] + 0xa679438e, 17); + MD5STEP (F1, b, c, d, a, in[15] + 0x49b40821, 22); + + MD5STEP (F2, a, b, c, d, in[1] + 0xf61e2562, 5); + MD5STEP (F2, d, a, b, c, in[6] + 0xc040b340, 9); + MD5STEP (F2, c, d, a, b, in[11] + 0x265e5a51, 14); + MD5STEP (F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); + MD5STEP (F2, a, b, c, d, in[5] + 0xd62f105d, 5); + MD5STEP (F2, d, a, b, c, in[10] + 0x02441453, 9); + MD5STEP (F2, c, d, a, b, in[15] + 0xd8a1e681, 14); + MD5STEP (F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); + MD5STEP (F2, a, b, c, d, in[9] + 0x21e1cde6, 5); + MD5STEP (F2, d, a, b, c, in[14] + 0xc33707d6, 9); + MD5STEP (F2, c, d, a, b, in[3] + 0xf4d50d87, 14); + MD5STEP (F2, b, c, d, a, in[8] + 0x455a14ed, 20); + MD5STEP (F2, a, b, c, d, in[13] + 0xa9e3e905, 5); + MD5STEP (F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); + MD5STEP (F2, c, d, a, b, in[7] + 0x676f02d9, 14); + MD5STEP (F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); + + MD5STEP (F3, a, b, c, d, in[5] + 0xfffa3942, 4); + MD5STEP (F3, d, a, b, c, in[8] + 0x8771f681, 11); + MD5STEP (F3, c, d, a, b, in[11] + 0x6d9d6122, 16); + MD5STEP (F3, b, c, d, a, in[14] + 0xfde5380c, 23); + MD5STEP (F3, a, b, c, d, in[1] + 0xa4beea44, 4); + MD5STEP (F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); + MD5STEP (F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); + MD5STEP (F3, b, c, d, a, in[10] + 0xbebfbc70, 23); + MD5STEP (F3, a, b, c, d, in[13] + 0x289b7ec6, 4); + MD5STEP (F3, d, a, b, c, in[0] + 0xeaa127fa, 11); + MD5STEP (F3, c, d, a, b, in[3] + 0xd4ef3085, 16); + MD5STEP (F3, b, c, d, a, in[6] + 0x04881d05, 23); + MD5STEP (F3, a, b, c, d, in[9] + 0xd9d4d039, 4); + MD5STEP (F3, d, a, b, c, in[12] + 0xe6db99e5, 11); + MD5STEP (F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); + MD5STEP (F3, b, c, d, a, in[2] + 0xc4ac5665, 23); + + MD5STEP (F4, a, b, c, d, in[0] + 0xf4292244, 6); + MD5STEP (F4, d, a, b, c, in[7] + 0x432aff97, 10); + MD5STEP (F4, c, d, a, b, in[14] + 0xab9423a7, 15); + MD5STEP (F4, b, c, d, a, in[5] + 0xfc93a039, 21); + MD5STEP (F4, a, b, c, d, in[12] + 0x655b59c3, 6); + MD5STEP (F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); + MD5STEP (F4, c, d, a, b, in[10] + 0xffeff47d, 15); + MD5STEP (F4, b, c, d, a, in[1] + 0x85845dd1, 21); + MD5STEP (F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); + MD5STEP (F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); + MD5STEP (F4, c, d, a, b, in[6] + 0xa3014314, 15); + MD5STEP (F4, b, c, d, a, in[13] + 0x4e0811a1, 21); + MD5STEP (F4, a, b, c, d, in[4] + 0xf7537e82, 6); + MD5STEP (F4, d, a, b, c, in[11] + 0xbd3af235, 10); + MD5STEP (F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); + MD5STEP (F4, b, c, d, a, in[9] + 0xeb86d391, 21); + + buf[0] += a; + buf[1] += b; + buf[2] += c; + buf[3] += d; +} + + + +/* When close is complete, there's no more work to do. */ +static void +digest_file_close_callback (GnomeVFSAsyncHandle *handle, + GnomeVFSResult result, + gpointer callback_data) +{ +} + +/* Close the file and then tell the caller we succeeded, handing off + * the buffer to the caller. + */ +static void +digest_file_completed (NautilusDigestFileHandle *digest_handle) +{ + guchar digest_result[16]; + char digest_string [33]; + char* hex_string = "0123456789abcdef"; + int index, result_index; + int current_value; + + gnome_vfs_async_close (digest_handle->handle, + digest_file_close_callback, + NULL); + + /* Invoke the callback to continue processing the annotation */ + md5_final (&digest_handle->digest_context, digest_result); + + /* make a hex string for the digest result */ + digest_string[32] = '\0'; + for (index = 0; index < 32; index++) { + current_value = digest_result[index >> 1]; + if (index & 1) { + result_index = current_value & 15; + } else { + result_index = (current_value >> 4) & 15; + } + + digest_string[index] = hex_string[result_index]; + } + + (* digest_handle->callback) (digest_handle->file, &digest_string[0]); + + g_free (digest_handle->buffer); + g_free (digest_handle); +} + +/* Tell the caller we failed. */ +static void +digest_file_failed (NautilusDigestFileHandle *digest_handle, GnomeVFSResult result) +{ + gnome_vfs_async_close (digest_handle->handle, + digest_file_close_callback, + NULL); + + g_free (digest_handle->buffer); + + (* digest_handle->callback) (digest_handle->file, NULL); + g_free (digest_handle); +} + +/* Here is the callback from the file read routine, where we actually accumulate the checksum */ +static void +calculate_checksum_callback (GnomeVFSAsyncHandle *handle, + GnomeVFSResult result, + gpointer buffer, + GnomeVFSFileSize bytes_requested, + GnomeVFSFileSize bytes_read, + gpointer callback_data) +{ + NautilusDigestFileHandle *digest_handle; + + /* Do a few reality checks. */ + g_assert (bytes_requested == READ_CHUNK_SIZE); + + digest_handle = callback_data; + g_assert (digest_handle->handle == handle); + g_assert (bytes_read <= bytes_requested); + + /* Check for a failure. */ + if (result != GNOME_VFS_OK && result != GNOME_VFS_ERROR_EOF) { + digest_file_failed (digest_handle, result); + return; + } + + /* accumulate the recently read data into the checksum */ + md5_update (&digest_handle->digest_context, buffer, bytes_read); + + /* Read more unless we are at the end of the file. */ + if (bytes_read > 0 && result == GNOME_VFS_OK) { + gnome_vfs_async_read (digest_handle->handle, + digest_handle->buffer, + READ_CHUNK_SIZE, + calculate_checksum_callback, + digest_handle); + } else { + digest_file_completed (digest_handle); + } +} + +/* Once the open is finished, read a first chunk. */ +static void +read_file_open_callback (GnomeVFSAsyncHandle *handle, + GnomeVFSResult result, + gpointer callback_data) +{ + NautilusDigestFileHandle *digest_handle; + + digest_handle = callback_data; + g_assert (digest_handle->handle == handle); + + /* Handle the failure case. */ + if (result != GNOME_VFS_OK) { + digest_file_failed (digest_handle, result); + return; + } + + /* read in the first chunk of the file */ + gnome_vfs_async_read (digest_handle->handle, + digest_handle->buffer, + READ_CHUNK_SIZE, + calculate_checksum_callback, + digest_handle); +} + + +/* calculate the digest for the passed-in file asynchronously, invoking the passed in + * callback when the calculation has been completed. + */ +static NautilusDigestFileHandle* +calculate_file_digest (NautilusFile *file, NautilusCalculateDigestCallback callback) +{ + NautilusDigestFileHandle *handle; + char *uri; + + /* allocate a digest-handle structure to keep our state */ + + handle = g_new0 (NautilusDigestFileHandle, 1); + uri = nautilus_file_get_uri (file); + + handle->callback = callback; + handle->file = file; + + /* allocate the buffer */ + handle->buffer = g_malloc (READ_CHUNK_SIZE); + + /* initialize the MD5 stuff */ + md5_init(&handle->digest_context); + + /* open the file */ + gnome_vfs_async_open (&handle->handle, + uri, + GNOME_VFS_OPEN_READ, + read_file_open_callback, + handle); + g_free (uri); + return handle; +} + +/* given a digest value, return the path to it in the local cache */ +static char * +get_annotation_path (const char *digest) +{ + char *user_directory, *annotation_directory; + char *annotation_path; + + user_directory = nautilus_get_user_directory (); + annotation_directory = nautilus_make_path (user_directory, "annotations"); + annotation_path = nautilus_make_path (annotation_directory, digest); + + g_free (user_directory); + g_free (annotation_directory); + return annotation_path; +} + +/* look up the passed-in digest in the local annotation cache */ +static char * +look_up_local_annotation (NautilusFile *file, const char *digest) +{ + GnomeVFSResult result; + int file_size; + char *uri, *path, *file_data; + + path = get_annotation_path (digest); + if (g_file_exists (path)) { + /* load the file and return it */ + uri = gnome_vfs_get_uri_from_local_path (path); + result = nautilus_read_entire_file (uri, &file_size, &file_data); + g_free (uri); + g_free (path); + if (result == GNOME_VFS_OK) { + return file_data; + } else { + return NULL; + } + } + g_free (path); + return NULL; +} + +static gboolean +has_local_annotation (const char *digest) +{ + gboolean has_annotation; + char *path; + + path = get_annotation_path (digest); + has_annotation = g_file_exists (path); + g_free (path); + return has_annotation; +} + +/* completion routine invoked when we've loaded the an annotation file from the service. + * We must parse it, and walk through it to save the annotations in the local cache. + */ + +static void +got_annotations_callback (GnomeVFSResult result, + GnomeVFSFileSize file_size, + char *file_contents, + gpointer callback_data) +{ + g_message ("got annotation callback, result is %d, file size is %d, file is %s", (int) result, (int) file_size, file_contents); +} + +/* format the request, and send it to the server */ +/* the first cut implementation simply sends the digests as a cgi parameter, + * but soon we'll want use SOAP or XML-RPC + */ +static void +fetch_annotations_from_server (void) +{ + GString *temp_string; + GList *current_entry, *save_entry; + char *uri; + + /* check to see if there are enough requests, or a long enough delay since the last one */ + + current_entry = annotation_request_queue; + save_entry = current_entry; + annotation_request_queue = NULL; + + /* simple cgi-based request format passed the digests as part of the uri, so + * gather the variable parts + */ + temp_string = g_string_new (""); + while (current_entry != NULL) { + g_string_append (temp_string, (char*) current_entry->data); + if (current_entry->next != NULL) { + g_string_append (temp_string, ","); + } + current_entry = current_entry->next; + } + + + uri = g_strdup_printf (SERVER_URI_TEMPLATE, temp_string->str); + g_string_free (temp_string, TRUE); + nautilus_g_list_free_deep (save_entry); + + g_message ("asking server for %s", uri); + + /* read the result from the server asynchronously */ + nautilus_read_entire_file_async (uri, got_annotations_callback, NULL); + g_free (uri); +} + +/* ask the server for an annotation asynchronously */ +static void +get_annotation_from_server (NautilusFile *file, const char *file_digest) +{ + /* add the request to the queue, and kick it off it there's enough of them */ + annotation_request_queue = g_list_prepend (annotation_request_queue, g_strdup (file_digest)); + fetch_annotations_from_server (); +} + +/* callback that's invokes when we've finished calculating the file's digest. Remember + * it in the metadata, and look up the associated annotation + */ +static void +got_file_digest (NautilusFile *file, const char *file_digest) +{ + /* save the digest in the file metadata */ + + if (file_digest == NULL) { + return; + } + + /* lookup the annotations associated with the file. If there is one, flag the change and we're done */ + if (has_local_annotation (file_digest)) { + nautilus_file_emit_changed (file); + return; + } + + /* there isn't a local annotation, so ask the server for one */ + get_annotation_from_server (file, file_digest); + return; +} + +/* return the annotation associated with a file. If we haven't inspected this file yet, + * return NULL but queue a request for an annotation lookup, which will be processed + * asynchronously and issue a "file_changed" signal if any is found. + */ +char *nautilus_annotation_get_annotation (NautilusFile *file) +{ + char *digest, *annotations; + + /* see if there's a digest available in metadata */ + digest = nautilus_file_get_metadata (file, NAUTILUS_METADATA_KEY_FILE_DIGEST, NULL); + + /* there isn't a digest, so start a request for one going, and return NULL */ + if (digest == NULL) { + calculate_file_digest (file, (NautilusCalculateDigestCallback) got_file_digest); + return NULL; + } + + /* there's a digest, so we if we have the annotations for the file cached locally */ + annotations = look_up_local_annotation (file, digest); + if (annotations != NULL) { + g_free (digest); + return annotations; + } + + /* we don't have a local annotation, so queue a request from the server */ + get_annotation_from_server (file, digest); + g_free (digest); + return NULL; +} + +/* return the number of annotations associated with the passed in file. If we don't know, + * return 0, but queue a request like above + */ +int nautilus_annotation_has_annotation (NautilusFile *file) +{ + return 0; +} + +/* add an annotation to a file */ +void nautilus_annotation_add_annotation (NautilusFile *file, const char *new_annotation) +{ +} + +/* remove an annotation from a file */ +void nautilus_annotation_remove_annotation (NautilusFile *file, int which_annotation) +{ +} + |