File size: 7,096 Bytes
bc32e7b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 | //! 图片下载、缓存、格式转换。
//!
//! 负责从网络获取图片、本地缓存检查、JPEG 转码等。
use std::path::{Path, PathBuf};
use image::GenericImageView;
use sha1::{Digest, Sha1};
use crate::base_system::context::Config;
use super::segment_shared::write_atomic;
// ── 哈希 ────────────────────────────────────────────────────────
pub(crate) fn sha1_hex(input: &str) -> String {
let mut hasher = Sha1::new();
hasher.update(input.as_bytes());
hex::encode(hasher.finalize())
}
// ── MIME / 扩展名 ───────────────────────────────────────────────
fn mime_from_ext(ext: &str) -> &'static str {
match ext {
".jpg" | ".jpeg" => "image/jpeg",
".png" => "image/png",
".gif" => "image/gif",
".webp" => "image/webp",
".avif" => "image/avif",
".heic" | ".heif" => "image/heic",
_ => "application/octet-stream",
}
}
fn sniff_mime_ext(bytes: &[u8]) -> (&'static str, &'static str) {
if bytes.len() >= 3 && bytes[0] == 0xFF && bytes[1] == 0xD8 && bytes[2] == 0xFF {
return ("image/jpeg", ".jpeg");
}
if bytes.len() >= 8
&& bytes[0] == 0x89
&& bytes[1] == 0x50
&& bytes[2] == 0x4E
&& bytes[3] == 0x47
&& bytes[4] == 0x0D
&& bytes[5] == 0x0A
&& bytes[6] == 0x1A
&& bytes[7] == 0x0A
{
return ("image/png", ".png");
}
if bytes.len() >= 6 && (&bytes[0..3] == b"GIF") {
return ("image/gif", ".gif");
}
if bytes.len() >= 12 && &bytes[0..4] == b"RIFF" && &bytes[8..12] == b"WEBP" {
return ("image/webp", ".webp");
}
// HEIC/HEIF detection: ISO BMFF 'ftyp' brand.
if bytes.len() >= 16 && &bytes[4..8] == b"ftyp" {
let brand = &bytes[8..12];
if brand == b"heic"
|| brand == b"heif"
|| brand == b"heix"
|| brand == b"mif1"
|| brand == b"msf1"
{
return ("image/heic", ".heic");
}
}
("application/octet-stream", "")
}
// ── JPEG 转码 ───────────────────────────────────────────────────
fn try_convert_to_jpeg(bytes: &[u8], quality: u8, max_dim: u32) -> Option<Vec<u8>> {
let mut img = image::load_from_memory(bytes).ok()?;
if max_dim > 0 {
let (w, h) = img.dimensions();
let longest = w.max(h);
if longest > max_dim {
let scale = max_dim as f32 / longest as f32;
let nw = ((w as f32) * scale).round().max(1.0) as u32;
let nh = ((h as f32) * scale).round().max(1.0) as u32;
img = img.resize_exact(nw, nh, image::imageops::FilterType::Lanczos3);
}
}
let rgb = img.to_rgb8();
let mut out = Vec::new();
{
let q = quality.clamp(1, 100);
let mut encoder = image::codecs::jpeg::JpegEncoder::new_with_quality(&mut out, q);
encoder
.encode(
&rgb,
rgb.width(),
rgb.height(),
image::ExtendedColorType::Rgb8,
)
.ok()?;
}
Some(out)
}
// ── 缓存查找 ────────────────────────────────────────────────────
fn find_cached_image(
images_dir: &Path,
hash: &str,
) -> Option<(PathBuf, &'static str, &'static str)> {
let exts = [
".jpeg", ".jpg", ".png", ".gif", ".webp", ".avif", ".heic", ".heif",
];
for ext in exts {
let p = images_dir.join(format!("{hash}{ext}"));
if p.exists() {
return Some((p, mime_from_ext(ext), ext));
}
}
None
}
// ── 网络获取 + 归一化 ──────────────────────────────────────────
fn fetch_and_normalize_image(
cfg: &Config,
url: &str,
) -> anyhow::Result<Option<(Vec<u8>, &'static str, &'static str)>> {
if !cfg.blocked_media_domains.is_empty() {
let lowered = url.to_ascii_lowercase();
if cfg
.blocked_media_domains
.iter()
.any(|d| !d.trim().is_empty() && lowered.contains(&d.to_ascii_lowercase()))
{
return Ok(None);
}
}
let bytes = match crate::third_party::media_fetch::fetch_bytes(
url,
std::time::Duration::from_millis(10_000),
) {
Some(b) => b,
None => return Ok(None),
};
let (mime, ext) = sniff_mime_ext(&bytes);
// 转码逻辑：
// - force_convert_images_to_jpeg=true：无条件尽量转
// - jpeg_retry_convert=true：当识别失败/或非 jpeg 时尝试转（可提升兼容性）
let should_try_jpeg = cfg.force_convert_images_to_jpeg
|| cfg.jpeg_retry_convert && (mime == "application/octet-stream" || mime != "image/jpeg");
if should_try_jpeg
&& mime != "image/heic"
&& let Some(jpeg) =
try_convert_to_jpeg(&bytes, cfg.jpeg_quality, cfg.media_max_dimension_px)
{
return Ok(Some((jpeg, "image/jpeg", ".jpeg")));
}
// HEIC/HEIF：image crate 无原生支持，无法解码。
// WebUI 封面已通过 HTML <img> 标签获取浏览器兼容格式，此处仅保留原始数据或跳过。
if mime == "image/heic" {
if cfg.keep_heic_original {
return Ok(Some((bytes, "image/heic", ext)));
}
tracing::debug!(url, "HEIC 格式图片，无法解码，跳过");
return Ok(None);
}
if mime == "application/octet-stream" {
return Ok(None);
}
Ok(Some((bytes, mime, ext)))
}
// ── 确保本地缓存 ───────────────────────────────────────────────
pub(crate) fn ensure_cached_image(
cfg: &Config,
url: &str,
images_dir: &Path,
) -> anyhow::Result<Option<(PathBuf, &'static str, &'static str)>> {
if !cfg.blocked_media_domains.is_empty() {
let lowered = url.to_ascii_lowercase();
if cfg
.blocked_media_domains
.iter()
.any(|d| !d.trim().is_empty() && lowered.contains(&d.to_ascii_lowercase()))
{
return Ok(None);
}
}
let hash = sha1_hex(url);
if let Some(hit) = find_cached_image(images_dir, &hash) {
return Ok(Some(hit));
}
let fetched = fetch_and_normalize_image(cfg, url)?;
let Some((bytes, mime, ext)) = fetched else {
return Ok(None);
};
std::fs::create_dir_all(images_dir)?;
let out_path = images_dir.join(format!("{hash}{ext}"));
if !out_path.exists() {
let _ = write_atomic(&out_path, &bytes);
}
Ok(Some((out_path, mime, ext)))
}
|