fiv/fiv-thumbnail.c

925 lines
28 KiB
C

//
// fiv-thumbnail.c: thumbnail management
//
// Copyright (c) 2021 - 2023, Přemysl Eric Janouch <p@janouch.name>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
#include "config.h"
#include <glib/gstdio.h>
#include <webp/demux.h>
#include <webp/encode.h>
#include <webp/mux.h>
#include <errno.h>
#include <math.h>
#include <stdbool.h>
#include <string.h>
#include "fiv-io.h"
#include "fiv-thumbnail.h"
#include "xdg.h"
#ifdef HAVE_LIBRAW
#include <libraw.h>
#if LIBRAW_VERSION >= LIBRAW_MAKE_VERSION(0, 21, 0)
#define LIBRAW_OPIONS_NO_MEMERR_CALLBACK 0
#endif
#endif // HAVE_LIBRAW
// TODO(p): Consider merging back with fiv-io.
#define FIV_THUMBNAIL_ERROR fiv_thumbnail_error_quark()
G_DEFINE_QUARK(fiv-thumbnail-error-quark, fiv_thumbnail_error)
enum FivThumbnailError {
FIV_THUMBNAIL_ERROR_IO
};
static void
set_error(GError **error, const char *message)
{
g_set_error_literal(
error, FIV_THUMBNAIL_ERROR, FIV_THUMBNAIL_ERROR_IO, message);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
GType
fiv_thumbnail_size_get_type(void)
{
static gsize guard;
if (g_once_init_enter(&guard)) {
#define XX(name, value, dir) {FIV_THUMBNAIL_SIZE_ ## name, \
"FIV_THUMBNAIL_SIZE_" #name, #name},
static const GEnumValue values[] = {FIV_THUMBNAIL_SIZES(XX) {}};
#undef XX
GType type = g_enum_register_static(
g_intern_static_string("FivThumbnailSize"), values);
g_once_init_leave(&guard, type);
}
return guard;
}
#define XX(name, value, dir) {value, dir},
FivThumbnailSizeInfo
fiv_thumbnail_sizes[FIV_THUMBNAIL_SIZE_COUNT] = {
FIV_THUMBNAIL_SIZES(XX)};
#undef XX
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
#define THUMB_URI "Thumb::URI"
#define THUMB_MTIME "Thumb::MTime"
#define THUMB_SIZE "Thumb::Size"
#define THUMB_IMAGE_WIDTH "Thumb::Image::Width"
#define THUMB_IMAGE_HEIGHT "Thumb::Image::Height"
#define THUMB_COLORSPACE "Thumb::ColorSpace"
#define THUMB_COLORSPACE_SRGB "sRGB"
cairo_user_data_key_t fiv_thumbnail_key_lq;
static void
mark_thumbnail_lq(cairo_surface_t *surface)
{
cairo_surface_set_user_data(
surface, &fiv_thumbnail_key_lq, (void *) (intptr_t) 1, NULL);
}
static gchar *
fiv_thumbnail_get_root(void)
{
gchar *cache_dir = get_xdg_home_dir("XDG_CACHE_HOME", ".cache");
gchar *thumbnails_dir = g_build_filename(cache_dir, "thumbnails", NULL);
g_free(cache_dir);
return thumbnails_dir;
}
static gboolean
might_be_a_thumbnail(const char *path_or_uri)
{
// It is generally difficult to discern case in/sensitivity of subpaths,
// so err on the side of false positives.
gchar *normalized = g_ascii_strdown(path_or_uri, -1);
// The Windows path separator must be percent-encoded in URIs,
// and the file scheme always uses forward slashes.
if (G_DIR_SEPARATOR != '/')
g_strdelimit(normalized, G_DIR_SEPARATOR_S, '/');
gboolean matches = strstr(normalized, "/.cache/thumbnails/") != NULL;
g_free(normalized);
return matches;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static cairo_surface_t *
render(GFile *target, GBytes *data, gboolean *color_managed, GError **error)
{
FivIoOpenContext ctx = {
.uri = g_file_get_uri(target),
.screen_profile = fiv_io_profile_new_sRGB(),
.screen_dpi = 96,
.first_frame_only = TRUE,
// Only using this array as a redirect.
.warnings = g_ptr_array_new_with_free_func(g_free),
};
cairo_surface_t *surface = fiv_io_open_from_data(
g_bytes_get_data(data, NULL), g_bytes_get_size(data), &ctx, error);
g_free((gchar *) ctx.uri);
g_ptr_array_free(ctx.warnings, TRUE);
if ((*color_managed = !!ctx.screen_profile))
fiv_io_profile_free(ctx.screen_profile);
g_bytes_unref(data);
return surface;
}
// In principle similar to rescale_thumbnail() from fiv-browser.c.
static cairo_surface_t *
adjust_thumbnail(cairo_surface_t *thumbnail, double row_height)
{
// Hardcode orientation.
FivIoOrientation orientation = (uintptr_t) cairo_surface_get_user_data(
thumbnail, &fiv_io_key_orientation);
double w = 0, h = 0;
cairo_matrix_t matrix =
fiv_io_orientation_apply(thumbnail, orientation, &w, &h);
double scale_x = 1;
double scale_y = 1;
if (w > FIV_THUMBNAIL_WIDE_COEFFICIENT * h) {
scale_x = FIV_THUMBNAIL_WIDE_COEFFICIENT * row_height / w;
scale_y = round(scale_x * h) / h;
} else {
scale_y = row_height / h;
scale_x = round(scale_y * w) / w;
}
// Vector images should not have orientation, this should handle them all.
FivIoRenderClosure *closure =
cairo_surface_get_user_data(thumbnail, &fiv_io_key_render);
if (closure && orientation <= FivIoOrientation0) {
// This API doesn't accept non-uniform scaling; prefer a vertical fit.
cairo_surface_t *scaled = closure->render(closure, scale_y);
if (scaled)
return scaled;
}
// This will be CAIRO_FORMAT_INVALID with non-image surfaces, which is fine.
cairo_format_t format = cairo_image_surface_get_format(thumbnail);
if (format != CAIRO_FORMAT_INVALID &&
orientation <= FivIoOrientation0 && scale_x == 1 && scale_y == 1)
return cairo_surface_reference(thumbnail);
int projected_width = round(scale_x * w);
int projected_height = round(scale_y * h);
cairo_surface_t *scaled = cairo_image_surface_create(
(format == CAIRO_FORMAT_RGB24 || format == CAIRO_FORMAT_RGB30)
? CAIRO_FORMAT_RGB24
: CAIRO_FORMAT_ARGB32,
projected_width, projected_height);
cairo_t *cr = cairo_create(scaled);
cairo_scale(cr, scale_x, scale_y);
cairo_set_source_surface(cr, thumbnail, 0, 0);
cairo_pattern_t *pattern = cairo_get_source(cr);
// CAIRO_FILTER_BEST, for some reason, works bad with CAIRO_FORMAT_RGB30.
cairo_pattern_set_filter(pattern, CAIRO_FILTER_GOOD);
cairo_pattern_set_extend(pattern, CAIRO_EXTEND_PAD);
cairo_pattern_set_matrix(pattern, &matrix);
cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
cairo_paint(cr);
// Note that this doesn't get triggered with oversize input surfaces,
// even though nothing will be rendered.
if (cairo_surface_status(thumbnail) != CAIRO_STATUS_SUCCESS ||
cairo_surface_status(scaled) != CAIRO_STATUS_SUCCESS ||
cairo_pattern_status(pattern) != CAIRO_STATUS_SUCCESS ||
cairo_status(cr) != CAIRO_STATUS_SUCCESS)
g_warning("thumbnail scaling failed");
cairo_destroy(cr);
return scaled;
}
static cairo_surface_t *
orient_thumbnail(cairo_surface_t *surface, FivIoOrientation orientation)
{
if (!surface || orientation <= FivIoOrientation0)
return surface;
double w = 0, h = 0;
cairo_matrix_t matrix =
fiv_io_orientation_apply(surface, orientation, &w, &h);
cairo_surface_t *oriented =
cairo_image_surface_create(CAIRO_FORMAT_RGB24, w, h);
cairo_t *cr = cairo_create(oriented);
cairo_set_source_surface(cr, surface, 0, 0);
cairo_pattern_set_matrix(cairo_get_source(cr), &matrix);
cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
cairo_paint(cr);
cairo_destroy(cr);
cairo_surface_destroy(surface);
return oriented;
}
cairo_surface_t *
fiv_thumbnail_extract(GFile *target, FivThumbnailSize max_size, GError **error)
{
const char *path = g_file_peek_path(target);
if (!path) {
set_error(error, "thumbnails will only be extracted from local files");
return NULL;
}
GMappedFile *mf = g_mapped_file_new(path, FALSE, error);
if (!mf)
return NULL;
// Bitmap thumbnails generally need rotating, e.g.:
// - Hasselblad/H4D-50/2-9-2017_street_0012.fff
// - OnePlus/One/IMG_20150729_201116.dng (and more DNGs in general)
// Though it's apparent LibRaw doesn't adjust the thumbnails to match
// the main image's "flip" field (it just happens to match up often), e.g.:
// - Phase One/H 25/H25_Outdoor_.IIQ (correct Orientation in IFD0)
// - Phase One/H 25/H25_IT8.7-2_Card.TIF (correctly missing in IFD0)
//
// JPEG thumbnails generally have the right rotation in their Exif, e.g.:
// - Canon/EOS-1Ds Mark II/RAW_CANON_1DSM2.CR2
// - Leica/C (Typ 112)/Leica_-_C_(Typ_112)-_3:2.RWL
// - Nikon/1 S2/RAW_NIKON_1S2.NEF
// - Panasonic/DMC-FZ18/RAW_PANASONIC_LUMIX_FZ18.RAW
// - Panasonic/DMC-FZ70/P1000836.RW2
// - Samsung/NX200/2013-05-08-194524__sam6589.srw
// - Sony/DSC-HX95/DSC00018.ARW
//
// Some files are problematic and we won't bother with special-casing:
// - Leaf/Aptus 22/L_003172.mos (JPEG)'s thumbnail wrongly contains
// Exif Orientation 6, and sizes.flip also contains 6.
// - Nokia/Lumia 1020/RAW_NOKIA_LUMIA_1020.DNG (bitmap) has wrong color.
// - Ricoh/GXR/R0017428.DNG (JPEG) seems to be plainly invalid.
FivIoOrientation orientation = FivIoOrientationUnknown;
cairo_surface_t *surface = NULL;
#ifndef HAVE_LIBRAW
// TODO(p): Implement our own thumbnail extractors.
set_error(error, "unsupported file");
#else // HAVE_LIBRAW
libraw_data_t *iprc = libraw_init(
LIBRAW_OPIONS_NO_MEMERR_CALLBACK | LIBRAW_OPIONS_NO_DATAERR_CALLBACK);
if (!iprc) {
set_error(error, "failed to obtain a LibRaw handle");
goto fail;
}
int err = 0;
if ((err = libraw_open_buffer(iprc, (void *) g_mapped_file_get_contents(mf),
g_mapped_file_get_length(mf))) ||
(err = libraw_unpack_thumb(iprc))) {
set_error(error, libraw_strerror(err));
goto fail_libraw;
}
libraw_processed_image_t *image = libraw_dcraw_make_mem_thumb(iprc, &err);
if (!image) {
set_error(error, libraw_strerror(err));
goto fail_libraw;
}
gboolean dummy = FALSE;
switch (image->type) {
case LIBRAW_IMAGE_JPEG:
surface = render(
target, g_bytes_new(image->data, image->data_size), &dummy, error);
orientation = (int) (intptr_t) cairo_surface_get_user_data(
surface, &fiv_io_key_orientation);
break;
case LIBRAW_IMAGE_BITMAP:
// Anything else is extremely rare.
if (image->colors != 3 || image->bits != 8) {
set_error(error, "unsupported bitmap thumbnail");
break;
}
surface = cairo_image_surface_create(
CAIRO_FORMAT_RGB24, image->width, image->height);
guint32 *out = (guint32 *) cairo_image_surface_get_data(surface);
const unsigned char *in = image->data;
for (guint64 i = 0; i < image->width * image->height; in += 3)
out[i++] = in[0] << 16 | in[1] << 8 | in[2];
cairo_surface_mark_dirty(surface);
// LibRaw actually turns an 8 to 5, so follow the documentation.
switch (iprc->sizes.flip) {
break; case 3: orientation = FivIoOrientation180;
break; case 5: orientation = FivIoOrientation270;
break; case 6: orientation = FivIoOrientation90;
}
break;
default:
set_error(error, "unsupported embedded thumbnail");
}
libraw_dcraw_clear_mem(image);
fail_libraw:
libraw_close(iprc);
#endif // HAVE_LIBRAW
fail:
g_mapped_file_unref(mf);
// This hardcodes Exif orientation before adjust_thumbnail() might do so,
// before the early return below.
surface = orient_thumbnail(surface, orientation);
if (!surface || max_size < FIV_THUMBNAIL_SIZE_MIN ||
max_size > FIV_THUMBNAIL_SIZE_MAX)
return surface;
cairo_surface_t *result =
adjust_thumbnail(surface, fiv_thumbnail_sizes[max_size].size);
cairo_surface_destroy(surface);
return result;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static WebPData
encode_thumbnail(cairo_surface_t *surface)
{
WebPData bitstream = {};
WebPConfig config = {};
if (!WebPConfigInit(&config) || !WebPConfigLosslessPreset(&config, 6))
return bitstream;
config.near_lossless = 95;
config.thread_level = true;
if (!WebPValidateConfig(&config))
return bitstream;
bitstream.bytes = fiv_io_encode_webp(surface, &config, &bitstream.size);
return bitstream;
}
static void
save_thumbnail(cairo_surface_t *thumbnail, const char *path, GString *thum)
{
WebPMux *mux = WebPMuxNew();
WebPData bitstream = encode_thumbnail(thumbnail);
gboolean ok = WebPMuxSetImage(mux, &bitstream, true) == WEBP_MUX_OK;
WebPDataClear(&bitstream);
WebPData data = {.bytes = (const uint8_t *) thum->str, .size = thum->len};
ok = ok && WebPMuxSetChunk(mux, "THUM", &data, false) == WEBP_MUX_OK;
WebPData assembled = {};
WebPDataInit(&assembled);
ok = ok && WebPMuxAssemble(mux, &assembled) == WEBP_MUX_OK;
WebPMuxDelete(mux);
if (!ok) {
g_warning("thumbnail encoding failed");
return;
}
GError *e = NULL;
while (!g_file_set_contents(
path, (const gchar *) assembled.bytes, assembled.size, &e)) {
bool missing_parents =
e->domain == G_FILE_ERROR && e->code == G_FILE_ERROR_NOENT;
g_debug("%s: %s", path, e->message);
g_clear_error(&e);
if (!missing_parents)
break;
gchar *dirname = g_path_get_dirname(path);
int err = g_mkdir_with_parents(dirname, 0755);
if (err)
g_debug("%s: %s", dirname, g_strerror(errno));
g_free(dirname);
if (err)
break;
}
// It would be possible to create square thumbnails as well,
// but it seems like wasted effort.
WebPDataClear(&assembled);
}
cairo_surface_t *
fiv_thumbnail_produce_for_search(
GFile *target, FivThumbnailSize max_size, GError **error)
{
g_return_val_if_fail(max_size >= FIV_THUMBNAIL_SIZE_MIN &&
max_size <= FIV_THUMBNAIL_SIZE_MAX, NULL);
GBytes *data = g_file_load_bytes(target, NULL, NULL, error);
if (!data)
return NULL;
gboolean color_managed = FALSE;
cairo_surface_t *surface = render(target, data, &color_managed, error);
if (!surface)
return NULL;
// TODO(p): Might want to keep this a square.
cairo_surface_t *result =
adjust_thumbnail(surface, fiv_thumbnail_sizes[max_size].size);
cairo_surface_destroy(surface);
return result;
}
static cairo_surface_t *
produce_fallback(GFile *target, FivThumbnailSize size, GError **error)
{
goffset filesize = 0;
GFileInfo *info = g_file_query_info(target,
G_FILE_ATTRIBUTE_STANDARD_NAME "," G_FILE_ATTRIBUTE_STANDARD_SIZE,
G_FILE_QUERY_INFO_NONE, NULL, NULL);
if (info) {
filesize = g_file_info_get_size(info);
g_object_unref(info);
}
// TODO(p): Try to be a bit more intelligent about this.
// For example, we can employ magic checks.
if (filesize > 10 << 20) {
set_error(error, "oversize, not thumbnailing");
return NULL;
}
GBytes *data = g_file_load_bytes(target, NULL, NULL, error);
if (!data)
return NULL;
gboolean color_managed = FALSE;
cairo_surface_t *surface = render(target, data, &color_managed, error);
if (!surface)
return NULL;
cairo_surface_t *result =
adjust_thumbnail(surface, fiv_thumbnail_sizes[size].size);
cairo_surface_destroy(surface);
return result;
}
cairo_surface_t *
fiv_thumbnail_produce(GFile *target, FivThumbnailSize max_size, GError **error)
{
g_return_val_if_fail(max_size >= FIV_THUMBNAIL_SIZE_MIN &&
max_size <= FIV_THUMBNAIL_SIZE_MAX, NULL);
// Don't save thumbnails for FUSE mounts, such as sftp://.
// Moreover, it doesn't make sense to save thumbnails of thumbnails.
const gchar *path = g_file_peek_path(target);
if (!path || !g_file_is_native(target) || might_be_a_thumbnail(path))
return produce_fallback(target, max_size, error);
// Make the TOCTTOU issue favour unnecessary reloading.
GStatBuf st = {};
if (g_stat(path, &st)) {
set_error(error, g_strerror(errno));
return NULL;
}
GError *e = NULL;
GMappedFile *mf = g_mapped_file_new(path, FALSE, &e);
if (!mf) {
g_debug("%s: %s", path, e->message);
g_error_free(e);
return produce_fallback(target, max_size, error);
}
gsize filesize = g_mapped_file_get_length(mf);
gboolean color_managed = FALSE;
cairo_surface_t *surface =
render(target, g_mapped_file_get_bytes(mf), &color_managed, error);
g_mapped_file_unref(mf);
if (!surface)
return NULL;
// Boilerplate copied from fiv_thumbnail_lookup().
gchar *uri = g_file_get_uri(target);
gchar *sum = g_compute_checksum_for_string(G_CHECKSUM_MD5, uri, -1);
gchar *thumbnails_dir = fiv_thumbnail_get_root();
GString *thum = g_string_new("");
g_string_append_printf(
thum, "%s%c%s%c", THUMB_URI, 0, uri, 0);
g_string_append_printf(
thum, "%s%c%ld%c", THUMB_MTIME, 0, (long) st.st_mtime, 0);
g_string_append_printf(
thum, "%s%c%llu%c", THUMB_SIZE, 0, (unsigned long long) filesize, 0);
if (cairo_surface_get_type(surface) == CAIRO_SURFACE_TYPE_IMAGE) {
g_string_append_printf(thum, "%s%c%d%c", THUMB_IMAGE_WIDTH, 0,
cairo_image_surface_get_width(surface), 0);
g_string_append_printf(thum, "%s%c%d%c", THUMB_IMAGE_HEIGHT, 0,
cairo_image_surface_get_height(surface), 0);
}
// Without a CMM, no conversion is attempted.
if (color_managed) {
g_string_append_printf(
thum, "%s%c%s%c", THUMB_COLORSPACE, 0, THUMB_COLORSPACE_SRGB, 0);
}
cairo_surface_t *max_size_surface = NULL;
for (int use = max_size; use >= FIV_THUMBNAIL_SIZE_MIN; use--) {
cairo_surface_t *scaled =
adjust_thumbnail(surface, fiv_thumbnail_sizes[use].size);
gchar *path = g_strdup_printf("%s/wide-%s/%s.webp", thumbnails_dir,
fiv_thumbnail_sizes[use].thumbnail_spec_name, sum);
save_thumbnail(scaled, path, thum);
g_free(path);
if (!max_size_surface)
max_size_surface = scaled;
else
cairo_surface_destroy(scaled);
}
g_string_free(thum, TRUE);
g_free(thumbnails_dir);
g_free(sum);
g_free(uri);
cairo_surface_destroy(surface);
return max_size_surface;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
typedef struct {
const char *uri; ///< Target URI
time_t mtime; ///< File modification time
guint64 size; ///< File size
} Stat;
static bool
check_wide_thumbnail_texts(GBytes *thum, const Stat *st, bool *sRGB)
{
gsize len = 0;
const gchar *s = g_bytes_get_data(thum, &len), *end = s + len;
// Similar to PNG below, but we're following our own specification.
const gchar *key = NULL, *nul = NULL;
bool have_uri = false, have_mtime = false;
for (; (nul = memchr(s, '\0', end - s)); s = ++nul) {
if (!key) {
key = s;
continue;
} else if (!strcmp(key, THUMB_URI)) {
have_uri = true;
if (strcmp(st->uri, s))
return false;
} else if (!strcmp(key, THUMB_MTIME)) {
have_mtime = true;
if (atol(s) != st->mtime)
return false;
} else if (!strcmp(key, THUMB_SIZE)) {
if (strtoull(s, NULL, 10) != st->size)
return false;
} else if (!strcmp(key, THUMB_COLORSPACE))
*sRGB = !strcmp(s, THUMB_COLORSPACE_SRGB);
key = NULL;
}
return have_uri && have_mtime;
}
static cairo_surface_t *
read_wide_thumbnail(const char *path, const Stat *st, GError **error)
{
gchar *thumbnail_uri = g_filename_to_uri(path, NULL, error);
if (!thumbnail_uri)
return NULL;
cairo_surface_t *surface =
fiv_io_open(&(FivIoOpenContext){.uri = thumbnail_uri}, error);
g_free(thumbnail_uri);
if (!surface)
return NULL;
bool sRGB = false;
GBytes *thum = cairo_surface_get_user_data(surface, &fiv_io_key_thum);
if (!thum) {
g_clear_error(error);
set_error(error, "not a thumbnail");
} else if (!check_wide_thumbnail_texts(thum, st, &sRGB)) {
g_clear_error(error);
set_error(error, "mismatch");
} else {
// TODO(p): Add a function or a non-valueless define to check
// for CMM presence, then remove this ifdef.
#ifdef HAVE_LCMS2
if (!sRGB)
mark_thumbnail_lq(surface);
#endif // HAVE_LCMS2
return surface;
}
cairo_surface_destroy(surface);
return NULL;
}
static cairo_surface_t *
read_png_thumbnail(const char *path, const Stat *st, GError **error)
{
cairo_surface_t *surface = fiv_io_open_png_thumbnail(path, error);
if (!surface)
return NULL;
GHashTable *texts = cairo_surface_get_user_data(surface, &fiv_io_key_text);
if (!texts) {
set_error(error, "not a thumbnail");
cairo_surface_destroy(surface);
return NULL;
}
// May contain Thumb::Image::Width Thumb::Image::Height,
// but those aren't interesting currently (would be for fast previews).
const char *text_uri = g_hash_table_lookup(texts, THUMB_URI);
const char *text_mtime = g_hash_table_lookup(texts, THUMB_MTIME);
const char *text_size = g_hash_table_lookup(texts, THUMB_SIZE);
if (!text_uri || strcmp(text_uri, st->uri) ||
!text_mtime || atol(text_mtime) != st->mtime) {
set_error(error, "mismatch or not a thumbnail");
cairo_surface_destroy(surface);
return NULL;
}
if (text_size && strtoull(text_size, NULL, 10) != st->size) {
set_error(error, "file size mismatch");
cairo_surface_destroy(surface);
return NULL;
}
return surface;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
cairo_surface_t *
fiv_thumbnail_lookup(const char *uri, gint64 mtime_msec, guint64 filesize,
FivThumbnailSize size)
{
g_return_val_if_fail(size >= FIV_THUMBNAIL_SIZE_MIN &&
size <= FIV_THUMBNAIL_SIZE_MAX, NULL);
// Don't waste time looking up something that shouldn't exist--
// thumbnail directories tend to get huge, and syscalls are expensive.
if (might_be_a_thumbnail(uri))
return NULL;
gchar *sum = g_compute_checksum_for_string(G_CHECKSUM_MD5, uri, -1);
gchar *thumbnails_dir = fiv_thumbnail_get_root();
const Stat st = {.uri = uri, .mtime = mtime_msec / 1000, .size = filesize};
// The lookup sequence is: nominal..max, then mirroring back to ..min.
cairo_surface_t *result = NULL;
GError *error = NULL;
for (int i = 0; i < FIV_THUMBNAIL_SIZE_COUNT; i++) {
FivThumbnailSize use = size + i;
if (use > FIV_THUMBNAIL_SIZE_MAX)
use = FIV_THUMBNAIL_SIZE_MAX - i;
const char *name = fiv_thumbnail_sizes[use].thumbnail_spec_name;
gchar *wide = g_strconcat(thumbnails_dir, G_DIR_SEPARATOR_S "wide-",
name, G_DIR_SEPARATOR_S, sum, ".webp", NULL);
result = read_wide_thumbnail(wide, &st, &error);
if (error) {
g_debug("%s: %s", wide, error->message);
g_clear_error(&error);
}
g_free(wide);
if (result) {
// Higher up we can't distinguish images smaller than the thumbnail.
// Also, try not to rescale the already rescaled.
if (use != size)
mark_thumbnail_lq(result);
break;
}
gchar *path = g_strconcat(thumbnails_dir, G_DIR_SEPARATOR_S,
name, G_DIR_SEPARATOR_S, sum, ".png", NULL);
result = read_png_thumbnail(path, &st, &error);
if (error) {
g_debug("%s: %s", path, error->message);
g_clear_error(&error);
}
g_free(path);
if (result) {
// Whatever produced it, we may be able to outclass it.
mark_thumbnail_lq(result);
break;
}
}
// TODO(p): We can definitely extract embedded thumbnails, but it should be
// done as a separate stage--the file may be stored on a slow device.
g_free(thumbnails_dir);
g_free(sum);
return result;
}
// --- Invalidation ------------------------------------------------------------
static void
print_error(GFile *file, GError *error)
{
gchar *name = g_file_get_parse_name(file);
g_printerr("%s: %s\n", name, error->message);
g_free(name);
g_error_free(error);
}
static gchar *
identify_wide_thumbnail(GMappedFile *mf, Stat *st, GError **error)
{
WebPDemuxer *demux = WebPDemux(&(WebPData) {
.bytes = (const uint8_t *) g_mapped_file_get_contents(mf),
.size = g_mapped_file_get_length(mf),
});
if (!demux) {
set_error(error, "demux failure while reading metadata");
return NULL;
}
WebPChunkIterator chunk_iter = {};
gchar *uri = NULL;
if (!WebPDemuxGetChunk(demux, "THUM", 1, &chunk_iter)) {
set_error(error, "missing THUM chunk");
goto fail;
}
// Similar to check_wide_thumbnail_texts(), but with a different purpose.
const char *p = (const char *) chunk_iter.chunk.bytes,
*end = p + chunk_iter.chunk.size, *key = NULL, *nul = NULL;
for (; (nul = memchr(p, '\0', end - p)); p = ++nul)
if (key) {
if (!strcmp(key, THUMB_URI) && !uri)
uri = g_strdup(p);
if (!strcmp(key, THUMB_MTIME))
st->mtime = atol(p);
if (!strcmp(key, THUMB_SIZE))
st->size = strtoull(p, NULL, 10);
key = NULL;
} else {
key = p;
}
if (!uri)
set_error(error, "missing target URI");
WebPDemuxReleaseChunkIterator(&chunk_iter);
fail:
WebPDemuxDelete(demux);
return uri;
}
static void
check_wide_thumbnail(GFile *thumbnail, GError **error)
{
// Not all errors are enough of a reason for us to delete something.
GError *tolerable_error = NULL;
const char *path = g_file_peek_path(thumbnail);
GMappedFile *mf = g_mapped_file_new(path, FALSE, &tolerable_error);
if (!mf) {
print_error(thumbnail, tolerable_error);
return;
}
// Note that we could enforce the presence of the size field in our spec.
Stat target_st = {.uri = NULL, .mtime = 0, .size = G_MAXUINT64};
gchar *target_uri = identify_wide_thumbnail(mf, &target_st, error);
g_mapped_file_unref(mf);
if (!target_uri)
return;
// This should not occur at all, we're being pedantic.
gchar *sum = g_compute_checksum_for_string(G_CHECKSUM_MD5, target_uri, -1);
gchar *expected_basename = g_strdup_printf("%s.webp", sum);
gchar *basename = g_path_get_basename(path);
gboolean match = !strcmp(basename, expected_basename);
g_free(basename);
g_free(expected_basename);
g_free(sum);
if (!match) {
set_error(error, "URI checksum mismatch");
g_free(target_uri);
return;
}
GFile *target = g_file_new_for_uri(target_uri);
g_free(target_uri);
GFileInfo *info = g_file_query_info(target,
G_FILE_ATTRIBUTE_STANDARD_NAME ","
G_FILE_ATTRIBUTE_STANDARD_SIZE ","
G_FILE_ATTRIBUTE_TIME_MODIFIED,
G_FILE_QUERY_INFO_NONE, NULL, &tolerable_error);
g_object_unref(target);
if (g_error_matches(tolerable_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND)) {
g_propagate_error(error, tolerable_error);
return;
} else if (tolerable_error) {
print_error(thumbnail, tolerable_error);
return;
}
guint64 filesize = g_file_info_get_size(info);
GDateTime *mdatetime = g_file_info_get_modification_date_time(info);
g_object_unref(info);
if (!mdatetime) {
set_error(&tolerable_error, "cannot retrieve file modification time");
print_error(thumbnail, tolerable_error);
return;
}
if (g_date_time_to_unix(mdatetime) != target_st.mtime)
set_error(error, "modification time mismatch");
else if (target_st.size != G_MAXUINT64 && filesize != target_st.size)
set_error(error, "file size mismatch");
g_date_time_unref(mdatetime);
}
static void
invalidate_wide_thumbnail(GFile *thumbnail)
{
// It's possible to lift that restriction in the future,
// but we need to codify how the modification time should be checked.
const char *path = g_file_peek_path(thumbnail);
if (!path) {
print_error(thumbnail,
g_error_new_literal(G_IO_ERROR, G_IO_ERROR_FAILED,
"thumbnails are expected to be local files"));
return;
}
// You cannot kill what you did not create.
if (!g_str_has_suffix(path, ".webp"))
return;
GError *error = NULL;
check_wide_thumbnail(thumbnail, &error);
if (error) {
g_debug("Deleting %s: %s", path, error->message);
g_clear_error(&error);
if (!g_file_delete(thumbnail, NULL, &error))
print_error(thumbnail, error);
}
}
static void
invalidate_wide_thumbnail_directory(GFile *directory)
{
GError *error = NULL;
GFileEnumerator *enumerator = g_file_enumerate_children(directory,
G_FILE_ATTRIBUTE_STANDARD_NAME "," G_FILE_ATTRIBUTE_STANDARD_TYPE,
G_FILE_QUERY_INFO_NONE, NULL, &error);
if (!enumerator) {
print_error(directory, error);
return;
}
GFileInfo *info = NULL;
GFile *child = NULL;
while (g_file_enumerator_iterate(enumerator, &info, &child, NULL, &error) &&
info != NULL) {
if (g_file_info_get_file_type(info) == G_FILE_TYPE_REGULAR)
invalidate_wide_thumbnail(child);
}
g_object_unref(enumerator);
if (error)
print_error(directory, error);
}
void
fiv_thumbnail_invalidate(void)
{
gchar *thumbnails_dir = fiv_thumbnail_get_root();
for (int i = 0; i < FIV_THUMBNAIL_SIZE_COUNT; i++) {
const char *name = fiv_thumbnail_sizes[i].thumbnail_spec_name;
gchar *dirname = g_strdup_printf("wide-%s", name);
GFile *dir = g_file_new_build_filename(thumbnails_dir, dirname, NULL);
g_free(dirname);
invalidate_wide_thumbnail_directory(dir);
g_object_unref(dir);
}
g_free(thumbnails_dir);
}