diff --git a/crates/format/src/fig.rs b/crates/format/src/fig.rs index 55a5d7c34..2a8b542e9 100644 --- a/crates/format/src/fig.rs +++ b/crates/format/src/fig.rs @@ -72,6 +72,9 @@ use kiwi::{Kv, Schema}; /// Largest `canvas.fig` member read, and largest decompressed chunk. const MAX_CANVAS: u64 = 256 * 1024 * 1024; const MAX_CHUNK: u64 = 512 * 1024 * 1024; +/// Longest image hash (bytes) an image is found by: `images/` names and embedded images both +/// stop at 64 bytes (128 hex digits). +pub(crate) const MAX_IMAGE_HASH: usize = 64; /// Largest image member read. const MAX_IMAGE: u64 = figcraft_doc::ImageData::MAX_BYTES; /// Total decompressed ZIP image bytes read per import: the native image budget (`IMAGE_BUDGET`) on @@ -138,10 +141,14 @@ fn import_with_image_limit(bytes: &[u8], name: &str, image_limit: u64) -> Result let max_nodes = layer_budget(packed); drop(message); let file_name = archive.file_name.as_deref().filter(|n| !n.trim().is_empty()).unwrap_or(name); - let (json, mut warnings, networks) = map::to_rest(&msg, file_name, max_nodes); + let (mut json, mut warnings, networks) = map::to_rest(&msg, file_name, max_nodes); // The message goes before the layers are built, so the images it carries are copied out first. let embedded = embedded_copies(&msg); drop(msg); + let aliases = embedded_aliases(&embedded, |hash| archive.has_image(hash)); + if !aliases.is_empty() { + canonical_image_refs(&mut json, &aliases); + } let images = |r: &str| archive.image(r).or_else(|| embedded.get(r).map(|b| b.to_vec())); let (mut doc, more) = crate::rest::import_with_networks(&json, &images, networks, max_nodes)?; let skipped = archive.image_budget.skipped.get(); @@ -224,9 +231,53 @@ fn embedded_copies(msg: &Kv) -> BTreeMap> { out } +/// Embedded images ([`embedded_copies`]) whose blob an earlier hash already names, each with that +/// hash. Hashes that also have an `images/` member keep their own name: the member is read first. +/// Pointing every alias at one name has the import copy and hash each blob once, however many +/// hashes a file points at it. +fn embedded_aliases(embedded: &BTreeMap>, in_zip: impl Fn(&str) -> bool) -> BTreeMap { + let mut first: BTreeMap = BTreeMap::new(); + let mut out = BTreeMap::new(); + for (hash, bytes) in embedded { + if in_zip(hash) { + continue; + } + // Hashes naming one blob share its copy, so the copy's address tells the blob. + let canonical = *first.entry(bytes.as_ptr() as usize).or_insert(hash); + if canonical != hash { + out.insert(hash.clone(), canonical.clone()); + } + } + out +} + +/// Rename every `imageRef` in REST `json` found in `aliases` to the name it maps to. +fn canonical_image_refs(json: &mut serde_json::Value, aliases: &BTreeMap) { + use serde_json::Value; + let mut pending = vec![json]; + while let Some(value) = pending.pop() { + match value { + Value::Object(fields) => { + for (key, field) in fields.iter_mut() { + match field { + Value::String(r) if key == "imageRef" => { + if let Some(canonical) = aliases.get(r.as_str()) { + r.clone_from(canonical); + } + } + _ => pending.push(field), + } + } + } + Value::Array(items) => pending.extend(items.iter_mut()), + _ => {} + } + } +} + /// The hash and blob index of an `Image` value whose `dataBlob` points at a usable blob. fn embedded_image(image: &Kv, blobs: &[Kv]) -> Option<(String, usize)> { - let hash = image.get("hash").and_then(Kv::bytes).filter(|h| !h.is_empty() && h.len() <= 64)?; + let hash = image.get("hash").and_then(Kv::bytes).filter(|h| !h.is_empty() && h.len() <= MAX_IMAGE_HASH)?; let Some(Kv::Uint(index)) = image.get("dataBlob") else { return None }; let index = usize::try_from(*index).ok()?; let bytes = blob(blobs, index)?; @@ -272,10 +323,15 @@ impl<'b> Archive<'b> { Ok(Archive { canvas, file_name, zip: Some(z), image_budget }) } + /// Whether `images/` has a member for image `hash`. + fn has_image(&self, hash: &str) -> bool { + self.zip.as_ref().is_some_and(|z| z.index_for_name(&format!("images/{hash}")).is_some()) + } + /// Bytes of image `hash` (lowercase hex) from `images/`. fn image(&self, hash: &str) -> Option> { let budget = &self.image_budget; - if hash.is_empty() || hash.len() > 128 || !hash.bytes().all(|b| b.is_ascii_hexdigit()) { + if hash.is_empty() || hash.len() > 2 * MAX_IMAGE_HASH || !hash.bytes().all(|b| b.is_ascii_hexdigit()) { return None; } // A clone shares the parsed directory and the bytes; the resolver only has shared access. diff --git a/crates/format/src/fig/map/image_filter_tests.rs b/crates/format/src/fig/map/image_filter_tests.rs index a8db39a77..e13a56e32 100644 --- a/crates/format/src/fig/map/image_filter_tests.rs +++ b/crates/format/src/fig/map/image_filter_tests.rs @@ -1,4 +1,5 @@ -//! Malformed image paint filters are skipped with a warning. +//! Malformed image paint filters are skipped with a warning, and image hashes too long to name +//! an image aren't spelled out. use super::*; @@ -25,3 +26,12 @@ fn boolean_filter_values_are_malformed_even_when_false() { assert!(warnings.iter().any(|warning| warning.contains(expected_warning)), "{warnings:?}"); } } + +#[test] +fn an_oversized_image_hash_is_not_spelled_out() { + let paint = |len: usize| Kv::Object(vec![("type", Kv::Enum("IMAGE")), ("image", Kv::Object(vec![("hash", Kv::Bytes(vec![0xab; len]))]))]); + let image_ref = |len: usize| super::paint(&paint(len), &mut |_| {}).and_then(|p| p.get("imageRef").cloned()); + assert_eq!(image_ref(20), Some(Value::String("ab".repeat(20)))); + assert_eq!(image_ref(crate::fig::MAX_IMAGE_HASH), Some(Value::String("ab".repeat(crate::fig::MAX_IMAGE_HASH)))); + assert_eq!(image_ref(crate::fig::MAX_IMAGE_HASH + 1), Some(Value::String(String::new()))); +} diff --git a/crates/format/src/fig/map/paint.rs b/crates/format/src/fig/map/paint.rs index 5b7121757..cf96c2bf0 100644 --- a/crates/format/src/fig/map/paint.rs +++ b/crates/format/src/fig/map/paint.rs @@ -162,8 +162,17 @@ pub(crate) fn paint(p: &Kv, warn: &mut dyn FnMut(String)) -> Option { o.insert("gradientStops".into(), Value::Array(stops)); } "IMAGE" => { - let hash: String = - p.get("image").and_then(|i| i.get("hash")).and_then(Kv::bytes).unwrap_or_default().iter().map(|b| format!("{b:02x}")).collect(); + // A hash longer than any the file's images can be named by resolves to nothing: it + // isn't spelled out, which a shared style would repeat for every layer using it. + let hash: String = p + .get("image") + .and_then(|i| i.get("hash")) + .and_then(Kv::bytes) + .filter(|h| h.len() <= crate::fig::MAX_IMAGE_HASH) + .unwrap_or_default() + .iter() + .map(|b| format!("{b:02x}")) + .collect(); o.insert("imageRef".into(), json!(hash)); let mode = p.get("imageScaleMode").and_then(Kv::str).unwrap_or("FILL"); o.insert("scaleMode".into(), json!(mode)); diff --git a/crates/format/src/fig/tests.rs b/crates/format/src/fig/tests.rs index 657f2f81d..2afae4361 100644 --- a/crates/format/src/fig/tests.rs +++ b/crates/format/src/fig/tests.rs @@ -795,6 +795,44 @@ fn hashes_naming_one_blob_share_one_copy_of_it() { assert_eq!(*copies[&"63".repeat(20)], [7; 16]); } +/// Hashes naming one blob are imported as one image: every alias is renamed to the first hash +/// before layers are built, so the blob is copied and hashed once, not once per hash. +#[test] +fn hashes_naming_one_blob_are_imported_once() { + let rect = |i: u64, hash: u8, blob: u64| { + let paint = o(vec![("type", e("IMAGE")), ("image", o(vec![("hash", Kv::Bytes(vec![hash; 20])), ("dataBlob", u(blob))]))]); + node(i, Some((1, &format!("{i:04}"))), "RECTANGLE", &format!("R{i}"), vec![("size", xy(10.0, 10.0)), ("fillPaints", arr(vec![paint]))]) + }; + let mut nodes = vec![node(0, None, "DOCUMENT", "D", vec![]), node(1, Some((0, "!")), "CANVAS", "P", vec![])]; + nodes.extend((2..42).map(|i| rect(i, i as u8, 0))); + let msg = o(vec![("nodeChanges", arr(nodes)), ("blobs", arr(vec![o(vec![("bytes", Kv::Bytes(png()))])]))]); + let copies = embedded_copies(&msg); + let aliases = embedded_aliases(&copies, |_| false); + assert_eq!(aliases.len(), 39); + assert!(aliases.values().all(|c| *c == "02".repeat(20))); + // A hash `images/` also holds keeps its own name. + assert!(!embedded_aliases(&copies, |h| h == "05".repeat(20)).contains_key(&"05".repeat(20))); + let (doc, warnings) = import(&canvas(&schema(), &msg), "x").unwrap(); + assert!(!warnings.iter().any(|w| w.contains("isn't in the file")), "{warnings:?}"); + assert_eq!(doc.images.len(), 1); + let key = doc.images.keys().next().unwrap(); + for i in 2..42 { + let figcraft_doc::color::PaintKind::Image(img) = &named(&doc, &format!("R{i}")).fills[0].kind else { panic!("not an image fill") }; + assert_eq!(&img.image, key); + } +} + +#[test] +fn image_refs_are_renamed_wherever_they_sit() { + let aliases: BTreeMap = [("b".to_string(), "a".to_string())].into(); + let mut json = serde_json::json!({"fills": [{"imageRef": "b"}, {"imageRef": "c"}], "styles": {"s": {"fills": [{"imageRef": "b"}]}}, "name": "b"}); + canonical_image_refs(&mut json, &aliases); + assert_eq!( + json, + serde_json::json!({"fills": [{"imageRef": "a"}, {"imageRef": "c"}], "styles": {"s": {"fills": [{"imageRef": "a"}]}}, "name": "b"}) + ); +} + mod image_budget { use super::*;