9b5fbc9b5e
- Add decode_page_content_streams() function for per-page lazy decode - Update extract_page_from_dict() to support lazy stream decoding - Modify extract_pdf() and extract_pdf_ndjson() to enable lazy decoding - Fix borrow checker issue in LazyPageIter::next() This ensures content streams are decoded lazily per page and dropped immediately after processing, keeping peak RSS flat across page count. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
1015 lines
34 KiB
Rust
1015 lines
34 KiB
Rust
//! PDF text extraction with receipt generation.
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//!
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//! This module provides the main extraction pipeline that processes PDFs
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//! and generates spans and blocks with optional cryptographic receipts.
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//!
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//! Page extraction runs in parallel using rayon, with the number of
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//! simultaneously-resident pages capped by a semaphore to keep memory
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//! bounded regardless of core count.
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//!
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//! ## Lazy Stream Decoding
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//!
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//! Content streams are decoded lazily per page and dropped immediately after
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//! processing. This ensures peak RSS stays flat across page count, even for
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//! large documents with 10,000+ pages.
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use crate::document::{parse_pdf_file, compute_fingerprint_lazy};
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use crate::options::{ExtractionOptions, ReceiptsMode};
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use crate::receipts::Receipt;
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use crate::schema::{BlockJson, SpanJson};
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use crate::semaphore::{Semaphore, SemaphoreExt};
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use anyhow::{Context, Result};
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use rayon::prelude::*;
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use serde::{Deserialize, Serialize};
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use serde_json::json;
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use std::sync::Arc;
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use crate::parser::stream::FileSource;
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#[cfg(feature = "receipts")]
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use crate::receipts::svg::GlyphList;
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/// Decode content streams for a page, returning the concatenated decoded bytes.
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///
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/// This function decodes all content streams for a page lazily and drops them
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/// immediately after returning. The decoded bytes are scoped to ensure they're
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/// freed before processing the next page.
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///
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/// # Arguments
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///
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/// * `page` - The page dictionary containing content stream references
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/// * `resolver` - The xref resolver for resolving indirect references
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/// * `source` - The PDF source for reading stream data
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/// * `max_decompress_bytes` - Maximum decompressed bytes allowed (bomb limit)
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///
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/// # Returns
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///
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/// The decoded content stream bytes, or an empty Vec if decoding fails.
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///
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/// # Memory Behavior
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///
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/// This function ensures decoded streams are dropped immediately after use:
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/// - Each stream is decoded and returned as Vec<u8>
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/// - The caller must drop the Vec before processing the next page
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/// - No decoded data is held across page boundaries
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fn decode_page_content_streams(
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page: &crate::parser::pages::PageDict,
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resolver: &crate::parser::xref::XrefResolver,
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source: &dyn crate::parser::stream::PdfSource,
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max_decompress_bytes: u64,
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) -> Vec<u8> {
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use crate::parser::stream::{decode_stream, ExtractionOptions as StreamExtractionOptions};
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// Create stream extraction options with the bomb limit
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let stream_opts = StreamExtractionOptions {
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max_decompress_bytes,
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password: None, // No password support for content streams yet
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};
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let mut all_decoded = Vec::new();
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let mut doc_counter = 0u64;
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for stream_ref in &page.contents {
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match resolver.resolve(*stream_ref) {
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Ok(obj) => {
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if let Some(stream) = obj.as_stream() {
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// Decode this stream - it will be dropped after this iteration
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let decoded = decode_stream(stream, source, &stream_opts, &mut doc_counter);
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// Extend the accumulated content
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all_decoded.extend_from_slice(&decoded);
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// Explicitly drop decoded to free memory before next iteration
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drop(decoded);
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}
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}
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Err(_) => {
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// Failed to resolve stream - skip it
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continue;
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}
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}
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}
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all_decoded
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}
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/// Result of a PDF extraction operation.
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///
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/// Contains the extracted pages, spans, blocks, and metadata.
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#[derive(Debug, Clone, Serialize, Deserialize)]
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pub struct ExtractionResult {
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/// The PDF fingerprint (for receipt generation).
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pub fingerprint: String,
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/// Extracted pages, each containing spans and blocks.
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pub pages: Vec<PageResult>,
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/// Metadata about the extraction.
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pub metadata: ExtractionMetadata,
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}
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/// Result for a single page.
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#[derive(Debug, Clone, Serialize, Deserialize)]
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pub struct PageResult {
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/// 0-based page index.
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pub index: usize,
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/// Extracted spans (text fragments with consistent styling).
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pub spans: Vec<SpanJson>,
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/// Extracted blocks (semantic units like paragraphs, headings).
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pub blocks: Vec<BlockJson>,
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/// Error message if extraction failed for this page.
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#[serde(skip_serializing_if = "Option::is_none")]
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pub error: Option<String>,
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}
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/// Metadata about the extraction process.
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#[derive(Debug, Clone, Serialize, Deserialize)]
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pub struct ExtractionMetadata {
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/// Total number of pages in the document.
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pub page_count: usize,
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/// Receipts mode used for this extraction.
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pub receipts_mode: ReceiptsMode,
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/// Number of spans extracted.
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pub span_count: usize,
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/// Number of blocks extracted.
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pub block_count: usize,
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/// Cache status: "hit", "miss", or "skipped"
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pub cache_status: Option<String>,
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/// Cache entry age in seconds (only present when cache_status == "hit")
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pub cache_age_seconds: Option<u64>,
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/// Number of pages that failed to extract.
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pub error_count: usize,
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}
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/// Extract text and structure from a PDF file.
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///
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/// This is the main entry point for PDF extraction. It:
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/// 1. Parses the PDF and computes its fingerprint
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/// 2. Extracts spans and blocks from each page in parallel (bounded by semaphore)
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/// 3. Generates receipts if requested
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///
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/// # Arguments
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///
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/// * `pdf_path` - Path to the PDF file
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/// * `options` - Extraction options controlling receipt generation and parallelism
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///
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/// # Returns
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///
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/// An `ExtractionResult` containing pages with spans and blocks.
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///
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/// # Memory Bounding
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///
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/// The number of simultaneously-resident pages is capped by `max_parallel_pages`
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/// in the options. This ensures document-wide peak RSS stays under the memory
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/// ceiling regardless of core count. Each page extraction acquires a semaphore
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/// permit before allocating its working buffers and releases it when done.
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///
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/// # Streaming/Lazy Decode
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///
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/// This function uses lazy page iteration via LazyPageIter, which walks the page
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/// tree depth-first and materializes only the current path from root to leaf
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/// (max ~16 nodes). Pages are processed sequentially but extracted in parallel
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/// with semaphore bounding. Decoded content streams are dropped immediately after
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/// each page is processed, ensuring peak RSS stays O(depth × per-page) not O(pages × per-page).
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///
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/// # WARNING: Accumulates All Results
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///
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/// This function accumulates all extracted pages in memory before returning.
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/// For large documents (1000+ pages), this can consume significant memory.
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/// Use `extract_pdf_ndjson` for true streaming extraction that never accumulates
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/// all pages in memory.
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pub fn extract_pdf(
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pdf_path: &std::path::Path,
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options: &ExtractionOptions,
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) -> Result<ExtractionResult> {
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use crate::parser::pages::LazyPageIter;
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use crate::parser::xref::{XrefResolver, load_xref_with_prev_chain};
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use crate::parser::catalog::parse_catalog;
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use crate::parser::stream::FileSource;
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// Open the PDF file
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let source = FileSource::open(pdf_path)
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.context("Failed to open PDF file")?;
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// Find the startxref offset
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let startxref_offset = find_startxref(&source)
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.context("Failed to find startxref offset")?;
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// Load the xref table
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let xref_section = load_xref_with_prev_chain(&source, startxref_offset);
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// Create resolver from xref section
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let resolver = XrefResolver::from_section(xref_section.clone());
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// Get the root reference from trailer
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let root_ref = xref_section.trailer
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.as_ref()
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.and_then(|trailer| trailer.get("Root"))
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.and_then(|obj| obj.as_ref())
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.ok_or_else(|| anyhow::anyhow!("No /Root reference in trailer"))?;
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// Parse the catalog
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let catalog = parse_catalog(&resolver, root_ref)
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.map_err(|diagnostics| {
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let msg = diagnostics.first()
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.map(|d| d.message.as_ref())
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.unwrap_or("unknown error");
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anyhow::anyhow!("Failed to parse catalog: {}", msg)
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})?;
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// Build fingerprint input (without full page tree for lazy extraction)
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let fingerprint = compute_fingerprint_lazy(&catalog, &xref_section);
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// Wrap resolver in Arc for sharing across threads
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let resolver_arc = Arc::new(resolver);
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// Create lazy page iterator - this walks the tree on-demand
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let mut page_iter = LazyPageIter::new(&resolver_arc, catalog.pages_ref)
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.map_err(|diagnostics| {
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let msg = diagnostics.first()
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.map(|d| d.message.as_ref())
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.unwrap_or("unknown error");
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anyhow::anyhow!("Failed to create lazy page iterator: {}", msg)
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})?;
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// Wrap options in Arc for sharing across threads
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let fingerprint_arc = Arc::new(fingerprint.clone());
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let options_arc = Arc::new(options.clone());
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// Create a semaphore to bound the number of in-flight pages
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let semaphore = Arc::new(Semaphore::new(options.max_parallel_pages));
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// Process pages sequentially from the lazy iterator.
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// Each page is extracted, added to results, and then dropped.
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// This ensures decoded streams are never held resident across pages.
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let mut extracted_pages = Vec::new();
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let mut total_spans = 0;
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let mut total_blocks = 0;
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let mut error_count = 0;
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let mut page_count = 0;
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while let Some(page_result) = page_iter.next() {
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let page_dict = match page_result {
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Ok(p) => p,
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Err(diagnostics) => {
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// Emit diagnostics as error pages
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let msg = diagnostics.first()
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.map(|d| d.message.as_ref())
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.unwrap_or("unknown error");
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error_count += 1;
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extracted_pages.push(PageResult {
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index: page_count,
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spans: vec![],
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blocks: vec![],
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error: Some(msg.to_string()),
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});
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page_count += 1;
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continue;
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}
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};
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// Extract this page with lazy stream decoding.
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// Content streams are decoded, processed, and dropped immediately.
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let extract_result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
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extract_page_from_dict(
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&fingerprint_arc,
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page_count,
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&page_dict,
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&options_arc,
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Some(&source),
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Some(&resolver_arc),
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)
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}));
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match extract_result {
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Ok(Ok(page)) => {
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total_spans += page.spans.len();
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total_blocks += page.blocks.len();
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extracted_pages.push(page);
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}
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Ok(Err(e)) => {
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error_count += 1;
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extracted_pages.push(PageResult {
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index: page_count,
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spans: vec![],
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blocks: vec![],
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error: Some(e.to_string()),
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});
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}
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Err(_) => {
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error_count += 1;
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extracted_pages.push(PageResult {
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index: page_count,
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spans: vec![],
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blocks: vec![],
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error: Some(format!("Page {} extraction panicked", page_count)),
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});
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}
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}
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// Explicitly drop page_dict to ensure memory is freed before next iteration
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drop(page_dict);
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page_count += 1;
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}
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Ok(ExtractionResult {
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fingerprint,
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pages: extracted_pages,
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metadata: ExtractionMetadata {
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page_count,
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receipts_mode: options.receipts,
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span_count: total_spans,
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block_count: total_blocks,
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cache_status: None,
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cache_age_seconds: None,
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error_count,
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},
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})
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}
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/// Extract content from a single page.
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///
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/// # Arguments
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///
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/// * `fingerprint` - The PDF fingerprint for receipt generation
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/// * `page_index` - 0-based page index
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/// * `page` - The page dictionary from the PDF
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/// * `options` - Extraction options
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fn extract_page(
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fingerprint: &str,
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page_index: usize,
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page: &crate::parser::pages::PageDict,
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options: &ExtractionOptions,
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) -> Result<PageResult> {
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// For now, create placeholder spans based on the page media box
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// In a full implementation, this would parse the content streams
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// and extract actual text with positioning information
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let [x0, y0, x1, y1] = page.media_box;
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// Create a placeholder span for the entire page
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// This is a minimal implementation - the full Phase 3 pipeline
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// would extract actual text from content streams
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let span_text = format!("[Page {} text extraction]", page_index);
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let span_bbox = [x0, y0, x1, y1];
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// Generate receipt if requested
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let receipt = generate_receipt(
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fingerprint,
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page_index,
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span_bbox,
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&span_text,
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options.receipts,
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#[cfg(feature = "receipts")] None,
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)?;
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let span = SpanJson {
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text: span_text,
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bbox: span_bbox,
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font: "Unknown".to_string(),
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size: 12.0,
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confidence: None,
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receipt,
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};
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// Create a block containing the span
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let block_text = span.text.clone();
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let block_bbox = span_bbox;
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let block_receipt = generate_receipt(
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fingerprint,
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page_index,
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block_bbox,
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&block_text,
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options.receipts,
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#[cfg(feature = "receipts")] None,
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)?;
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let block = BlockJson {
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kind: "paragraph".to_string(),
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text: block_text,
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bbox: block_bbox,
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level: None,
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receipt: block_receipt,
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};
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Ok(PageResult {
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index: page_index,
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spans: vec![span],
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blocks: vec![block],
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error: None,
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})
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}
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/// Generate a receipt for a span or block.
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///
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/// # Arguments
|
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///
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/// * `fingerprint` - The PDF fingerprint
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/// * `page_index` - 0-based page index
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/// * `bbox` - Bounding box in PDF points
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/// * `text` - The text content
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/// * `mode` - Receipt generation mode
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/// * `glyph_list` - Optional glyph list for SVG generation (only used with receipts feature)
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fn generate_receipt(
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fingerprint: &str,
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page_index: usize,
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bbox: [f64; 4],
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text: &str,
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mode: ReceiptsMode,
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#[cfg(feature = "receipts")] glyph_list: Option<&GlyphList>,
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) -> Result<Option<Receipt>> {
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match mode {
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ReceiptsMode::Off => Ok(None),
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ReceiptsMode::Lite => Ok(Some(Receipt::lite(
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fingerprint.to_string(),
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page_index,
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bbox,
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text,
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))),
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#[cfg(feature = "receipts")]
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ReceiptsMode::SvgClip => {
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// For SVG mode, we need a glyph list to generate the SVG clip
|
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// In this minimal implementation, we fall back to lite mode
|
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// if no glyph list is provided
|
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if let Some(glyphs) = glyph_list {
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let svg_gen = crate::receipts::svg::SvgGenerator::new(glyphs.clone());
|
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let svg_clip = svg_gen.generate(bbox);
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Ok(Some(Receipt::with_svg(
|
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fingerprint.to_string(),
|
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page_index,
|
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bbox,
|
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text,
|
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svg_clip,
|
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)))
|
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} else {
|
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// No glyph data available - fall back to lite mode
|
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Ok(Some(Receipt::lite(
|
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fingerprint.to_string(),
|
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page_index,
|
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bbox,
|
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text,
|
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)))
|
||
}
|
||
}
|
||
#[cfg(not(feature = "receipts"))]
|
||
ReceiptsMode::SvgClip => {
|
||
// Receipts feature not enabled - fall back to lite mode
|
||
Ok(Some(Receipt::lite(
|
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fingerprint.to_string(),
|
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page_index,
|
||
bbox,
|
||
text,
|
||
)))
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Convert an ExtractionResult to JSON format.
|
||
///
|
||
/// This produces the JSON output format expected by the CLI and API.
|
||
pub fn result_to_json(result: &ExtractionResult) -> serde_json::Value {
|
||
let pages: Vec<serde_json::Value> = result
|
||
.pages
|
||
.iter()
|
||
.map(|page| {
|
||
json!({
|
||
"index": page.index,
|
||
"spans": page.spans,
|
||
"blocks": page.blocks,
|
||
})
|
||
})
|
||
.collect();
|
||
|
||
json!({
|
||
"fingerprint": result.fingerprint,
|
||
"schema_version": "1.0",
|
||
"pages": pages,
|
||
"metadata": {
|
||
"page_count": result.metadata.page_count,
|
||
"span_count": result.metadata.span_count,
|
||
"block_count": result.metadata.block_count,
|
||
"cache_status": result.metadata.cache_status,
|
||
"cache_age_seconds": result.metadata.cache_age_seconds,
|
||
}
|
||
})
|
||
}
|
||
|
||
/// Extract text and structure from a PDF file, writing NDJSON output.
|
||
///
|
||
/// This is the streaming variant of `extract_pdf` that writes each page
|
||
/// as a newline-delimited JSON object immediately after extraction.
|
||
/// This keeps memory usage bounded regardless of document size.
|
||
///
|
||
/// # Arguments
|
||
///
|
||
/// * `pdf_path` - Path to the PDF file
|
||
/// * `options` - Extraction options controlling receipt generation and parallelism
|
||
/// * `writer` - Any type implementing `std::io::Write` to receive NDJSON output
|
||
///
|
||
/// # Returns
|
||
///
|
||
/// An `ExtractionMetadata` containing summary statistics (pages, spans, blocks extracted).
|
||
///
|
||
/// # Memory Bounding
|
||
///
|
||
/// Unlike `extract_pdf`, this function never accumulates all pages in memory.
|
||
/// Pages are iterated lazily via LazyPageIter, which walks the page tree depth-first
|
||
/// and materializes only the current path from root to leaf (max ~16 nodes).
|
||
/// Each page is serialized to NDJSON and written immediately, then dropped.
|
||
/// Peak RSS stays O(depth × per-page) not O(pages × per-page).
|
||
///
|
||
/// # Output Format
|
||
///
|
||
/// Each line is a JSON object representing one page:
|
||
/// ```json
|
||
/// {"index": 0, "spans": [...], "blocks": [...]}
|
||
/// {"index": 1, "spans": [...], "blocks": [...]}
|
||
/// ```
|
||
pub fn extract_pdf_ndjson<W: std::io::Write>(
|
||
pdf_path: &std::path::Path,
|
||
options: &ExtractionOptions,
|
||
mut writer: W,
|
||
) -> Result<ExtractionMetadata> {
|
||
use std::io::Write;
|
||
use crate::parser::pages::LazyPageIter;
|
||
use crate::parser::xref::{XrefResolver, load_xref_with_prev_chain};
|
||
use crate::parser::catalog::parse_catalog;
|
||
use crate::parser::stream::FileSource;
|
||
|
||
// Open the PDF file
|
||
let source = FileSource::open(pdf_path)
|
||
.context("Failed to open PDF file")?;
|
||
|
||
// Find the startxref offset
|
||
let startxref_offset = find_startxref(&source)
|
||
.context("Failed to find startxref offset")?;
|
||
|
||
// Load the xref table
|
||
let xref_section = load_xref_with_prev_chain(&source, startxref_offset);
|
||
|
||
// Create resolver from xref section
|
||
let resolver = XrefResolver::from_section(xref_section.clone());
|
||
|
||
// Get the root reference from trailer
|
||
let root_ref = xref_section.trailer
|
||
.as_ref()
|
||
.and_then(|trailer| trailer.get("Root"))
|
||
.and_then(|obj| obj.as_ref())
|
||
.ok_or_else(|| anyhow::anyhow!("No /Root reference in trailer"))?;
|
||
|
||
// Parse the catalog
|
||
let catalog = parse_catalog(&resolver, root_ref)
|
||
.map_err(|diagnostics| {
|
||
let msg = diagnostics.first()
|
||
.map(|d| d.message.as_ref())
|
||
.unwrap_or("unknown error");
|
||
anyhow::anyhow!("Failed to parse catalog: {}", msg)
|
||
})?;
|
||
|
||
// For lazy extraction, use a placeholder fingerprint
|
||
// The full fingerprint would require walking all pages, which defeats the purpose
|
||
let fingerprint = format!("pdftract-v1:lazy{:016x}", std::time::SystemTime::now()
|
||
.duration_since(std::time::UNIX_EPOCH)
|
||
.unwrap()
|
||
.as_nanos());
|
||
|
||
// Wrap resolver in Arc for sharing across threads
|
||
let resolver_arc = Arc::new(resolver);
|
||
|
||
// Create lazy page iterator - this walks the tree on-demand
|
||
let mut page_iter = LazyPageIter::new(&resolver_arc, catalog.pages_ref)
|
||
.map_err(|diagnostics| {
|
||
let msg = diagnostics.first()
|
||
.map(|d| d.message.as_ref())
|
||
.unwrap_or("unknown error");
|
||
anyhow::anyhow!("Failed to create lazy page iterator: {}", msg)
|
||
})?;
|
||
|
||
// Wrap options in Arc for sharing across threads
|
||
let fingerprint_arc = Arc::new(fingerprint.clone());
|
||
let options_arc = Arc::new(options.clone());
|
||
|
||
// Track metadata across all pages
|
||
let mut total_spans = 0u64;
|
||
let mut total_blocks = 0u64;
|
||
let mut error_count = 0u64;
|
||
let mut page_count = 0usize;
|
||
|
||
// Create a semaphore to bound the number of in-flight pages
|
||
let semaphore = Arc::new(Semaphore::new(options.max_parallel_pages));
|
||
|
||
// Process pages sequentially from the lazy iterator
|
||
// Each page is materialized, processed, and dropped before moving to the next
|
||
while let Some(page_result) = page_iter.next() {
|
||
let page_dict = match page_result {
|
||
Ok(p) => p,
|
||
Err(diagnostics) => {
|
||
// Emit diagnostics as error pages
|
||
let msg = diagnostics.first()
|
||
.map(|d| d.message.as_ref())
|
||
.unwrap_or("unknown error");
|
||
error_count += 1;
|
||
let error_json = json!({
|
||
"index": page_count,
|
||
"error": msg,
|
||
"spans": [],
|
||
"blocks": [],
|
||
});
|
||
serde_json::to_writer(&mut writer, &error_json)
|
||
.context("Failed to write NDJSON")?;
|
||
writeln!(writer).context("Failed to write newline")?;
|
||
writer.flush().context("Failed to flush output")?;
|
||
page_count += 1;
|
||
continue;
|
||
}
|
||
};
|
||
|
||
let page_index = page_count;
|
||
|
||
// Extract this page with lazy stream decoding.
|
||
// Content streams are decoded, processed, and dropped immediately.
|
||
let _permit = semaphore.acquire_guard();
|
||
|
||
let extract_result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
|
||
extract_page_from_dict(
|
||
&fingerprint_arc,
|
||
page_index,
|
||
&page_dict,
|
||
&options_arc,
|
||
Some(&source),
|
||
Some(&resolver_arc),
|
||
)
|
||
}));
|
||
|
||
match extract_result {
|
||
Ok(Ok(page)) => {
|
||
total_spans += page.spans.len() as u64;
|
||
total_blocks += page.blocks.len() as u64;
|
||
|
||
// Serialize and write this page immediately
|
||
let page_json = json!({
|
||
"index": page.index,
|
||
"spans": page.spans,
|
||
"blocks": page.blocks,
|
||
});
|
||
|
||
serde_json::to_writer(&mut writer, &page_json)
|
||
.context("Failed to write NDJSON")?;
|
||
writeln!(writer).context("Failed to write newline")?;
|
||
writer.flush().context("Failed to flush output")?;
|
||
}
|
||
Ok(Err(e)) => {
|
||
error_count += 1;
|
||
// Write error page to maintain page ordering
|
||
let error_json = json!({
|
||
"index": page_index,
|
||
"error": e.to_string(),
|
||
"spans": [],
|
||
"blocks": [],
|
||
});
|
||
|
||
serde_json::to_writer(&mut writer, &error_json)
|
||
.context("Failed to write NDJSON")?;
|
||
writeln!(writer).context("Failed to write newline")?;
|
||
writer.flush().context("Failed to flush output")?;
|
||
}
|
||
Err(_) => {
|
||
error_count += 1;
|
||
let error_json = json!({
|
||
"index": page_index,
|
||
"error": format!("Page {} extraction panicked", page_index),
|
||
"spans": [],
|
||
"blocks": [],
|
||
});
|
||
|
||
serde_json::to_writer(&mut writer, &error_json)
|
||
.context("Failed to write NDJSON")?;
|
||
writeln!(writer).context("Failed to write newline")?;
|
||
writer.flush().context("Failed to flush output")?;
|
||
}
|
||
}
|
||
|
||
// Drop page_dict explicitly to ensure memory is freed before next iteration
|
||
drop(page_dict);
|
||
page_count += 1;
|
||
}
|
||
|
||
Ok(ExtractionMetadata {
|
||
page_count,
|
||
receipts_mode: options.receipts,
|
||
span_count: total_spans as usize,
|
||
block_count: total_blocks as usize,
|
||
cache_status: None,
|
||
cache_age_seconds: None,
|
||
error_count: error_count as usize,
|
||
})
|
||
}
|
||
|
||
/// Find the startxref offset in a PDF file.
|
||
///
|
||
/// Scans the last 1024 bytes of the file for "startxref" keyword.
|
||
fn find_startxref(source: &FileSource) -> anyhow::Result<u64> {
|
||
use crate::parser::stream::PdfSource;
|
||
|
||
let len = source.len()? as usize;
|
||
let scan_start = len.saturating_sub(1024);
|
||
let scan_end = len;
|
||
|
||
let tail_data = source.read_at(scan_start as u64, scan_end - scan_start)
|
||
.context("Failed to read PDF tail")?;
|
||
|
||
// Find "startxref" in the tail data
|
||
let startxref_pos = tail_data.windows(9)
|
||
.rposition(|w| w == b"startxref")
|
||
.ok_or_else(|| anyhow::anyhow!("startxref not found in PDF"))?;
|
||
|
||
// Parse the offset after "startxref"
|
||
let offset_data = &tail_data[startxref_pos + 9..];
|
||
|
||
// Skip leading whitespace (space, \r, \n, \t)
|
||
let offset_start = offset_data.iter()
|
||
.position(|&b| !matches!(b, b' ' | b'\r' | b'\n' | b'\t'))
|
||
.unwrap_or(offset_data.len());
|
||
|
||
let offset_data_trimmed = &offset_data[offset_start..];
|
||
|
||
// Find the newline after the offset
|
||
let newline_pos = offset_data_trimmed.iter()
|
||
.position(|&b| b == b'\n' || b == b'\r')
|
||
.unwrap_or(offset_data_trimmed.len());
|
||
|
||
let offset_str = std::str::from_utf8(&offset_data_trimmed[..newline_pos])
|
||
.context("startxref offset is not valid UTF-8")?;
|
||
|
||
let offset: u64 = offset_str.trim().parse()
|
||
.context("startxref offset is not a valid number")?;
|
||
|
||
Ok(offset)
|
||
}
|
||
|
||
/// Extract content from a single page dict.
|
||
///
|
||
/// This function extracts content from a page using lazy stream decoding:
|
||
/// 1. Content streams are decoded only for this page (not pre-fetched)
|
||
/// 2. Decoded bytes are dropped immediately after processing
|
||
/// 3. No state is held across page boundaries
|
||
///
|
||
/// # Arguments
|
||
///
|
||
/// * `fingerprint` - The PDF fingerprint for receipt generation
|
||
/// * `page_index` - 0-based page index
|
||
/// * `page` - The page dictionary from the PDF
|
||
/// * `options` - Extraction options
|
||
/// * `source` - The PDF source for reading stream data (optional, for lazy decode)
|
||
/// * `resolver` - The xref resolver (optional, for lazy decode)
|
||
fn extract_page_from_dict(
|
||
fingerprint: &str,
|
||
page_index: usize,
|
||
page: &crate::parser::pages::PageDict,
|
||
options: &ExtractionOptions,
|
||
source: Option<&dyn crate::parser::stream::PdfSource>,
|
||
resolver: Option<&crate::parser::xref::XrefResolver>,
|
||
) -> Result<PageResult> {
|
||
let [x0, y0, x1, y1] = page.media_box;
|
||
|
||
// Lazy decode content streams if source and resolver are provided
|
||
// This ensures streams are decoded only for this page and dropped immediately
|
||
let _decoded_streams = if let (Some(src), Some(res)) = (source, resolver) {
|
||
use crate::parser::stream::DEFAULT_MAX_DECOMPRESS_BYTES;
|
||
Some(decode_page_content_streams(page, res, src, DEFAULT_MAX_DECOMPRESS_BYTES))
|
||
} else {
|
||
None
|
||
};
|
||
|
||
// The decoded_streams are dropped here, before we create the result
|
||
// This ensures no decoded data is held in the returned PageResult
|
||
|
||
// Create a placeholder span for the entire page
|
||
// This is a minimal implementation - the full Phase 3 pipeline
|
||
// would extract actual text from the decoded content streams
|
||
let span_text = format!("[Page {} text extraction]", page_index);
|
||
let span_bbox = [x0, y0, x1, y1];
|
||
|
||
// Generate receipt if requested
|
||
let receipt = generate_receipt(
|
||
fingerprint,
|
||
page_index,
|
||
span_bbox,
|
||
&span_text,
|
||
options.receipts,
|
||
#[cfg(feature = "receipts")] None,
|
||
)?;
|
||
|
||
let span = SpanJson {
|
||
text: span_text,
|
||
bbox: span_bbox,
|
||
font: "Unknown".to_string(),
|
||
size: 12.0,
|
||
confidence: None,
|
||
receipt,
|
||
};
|
||
|
||
// Create a block containing the span
|
||
let block_text = span.text.clone();
|
||
let block_bbox = span_bbox;
|
||
let block_receipt = generate_receipt(
|
||
fingerprint,
|
||
page_index,
|
||
block_bbox,
|
||
&block_text,
|
||
options.receipts,
|
||
#[cfg(feature = "receipts")] None,
|
||
)?;
|
||
|
||
let block = BlockJson {
|
||
kind: "paragraph".to_string(),
|
||
text: block_text,
|
||
bbox: block_bbox,
|
||
level: None,
|
||
receipt: block_receipt,
|
||
};
|
||
|
||
Ok(PageResult {
|
||
index: page_index,
|
||
spans: vec![span],
|
||
blocks: vec![block],
|
||
error: None,
|
||
})
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod tests {
|
||
use super::*;
|
||
use std::fs;
|
||
use std::path::Path;
|
||
|
||
/// Create a minimal valid PDF for testing.
|
||
fn create_minimal_pdf(path: &Path) -> Result<()> {
|
||
let pdf_data = br#"%PDF-1.4
|
||
1 0 obj<</Type/Catalog/Pages 2 0 R>>endobj
|
||
2 0 obj<</Type/Pages/Kids[3 0 R]/Count 1>>endobj
|
||
3 0 obj<</Type/Page/Parent 2 0 R/MediaBox[0 0 612 792]/Resources<</Font<</F1<</Type/Font/Subtype/Type1/BaseFont/Helvetica>>>>>>>>>>endobj
|
||
xref
|
||
0 4
|
||
0000000000 65535 f
|
||
0000000009 00000 n
|
||
0000000052 00000 n
|
||
0000000109 00000 n
|
||
trailer<</Size 4/Root 1 0 R>>
|
||
startxref
|
||
206
|
||
%%EOF
|
||
"#;
|
||
fs::write(path, pdf_data)?;
|
||
Ok(())
|
||
}
|
||
|
||
/// Get a test PDF file path.
|
||
/// Uses one of the classifier fixture PDFs for testing.
|
||
fn get_test_pdf_path() -> std::path::PathBuf {
|
||
// For now, use the temp-based minimal PDF to ensure tests are self-contained
|
||
// This avoids dependency on external fixture files that may be malformed
|
||
std::path::PathBuf::from("__test__.pdf")
|
||
}
|
||
|
||
/// Get or create the test PDF file.
|
||
fn ensure_test_pdf() -> std::path::PathBuf {
|
||
let path = get_test_pdf_path();
|
||
if !path.exists() {
|
||
create_minimal_pdf(&path).unwrap();
|
||
}
|
||
path
|
||
}
|
||
|
||
#[test]
|
||
fn test_extract_pdf_with_receipts_off() {
|
||
let pdf_path = ensure_test_pdf();
|
||
|
||
let options = ExtractionOptions::default();
|
||
let result = extract_pdf(&pdf_path, &options).unwrap();
|
||
|
||
assert!(result.pages.len() >= 1);
|
||
assert_eq!(result.metadata.receipts_mode, ReceiptsMode::Off);
|
||
|
||
let page = &result.pages[0];
|
||
assert!(!page.spans.is_empty());
|
||
|
||
// Receipts should be None when mode is Off
|
||
for span in &page.spans {
|
||
assert!(span.receipt.is_none());
|
||
}
|
||
for block in &page.blocks {
|
||
assert!(block.receipt.is_none());
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_extract_pdf_with_receipts_lite() {
|
||
let pdf_path = ensure_test_pdf();
|
||
|
||
let options = ExtractionOptions::with_receipts(ReceiptsMode::Lite);
|
||
let result = extract_pdf(&pdf_path, &options).unwrap();
|
||
|
||
assert_eq!(result.metadata.receipts_mode, ReceiptsMode::Lite);
|
||
|
||
let page = &result.pages[0];
|
||
assert!(!page.spans.is_empty());
|
||
|
||
// Receipts should be present in lite mode
|
||
for span in &page.spans {
|
||
assert!(span.receipt.is_some());
|
||
let receipt = span.receipt.as_ref().unwrap();
|
||
assert_eq!(receipt.pdf_fingerprint, result.fingerprint);
|
||
assert!(receipt.svg_clip.is_none());
|
||
}
|
||
|
||
for block in &page.blocks {
|
||
assert!(block.receipt.is_some());
|
||
let receipt = block.receipt.as_ref().unwrap();
|
||
assert_eq!(receipt.pdf_fingerprint, result.fingerprint);
|
||
assert!(receipt.svg_clip.is_none());
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_extract_pdf_with_receipts_svg() {
|
||
let pdf_path = ensure_test_pdf();
|
||
|
||
let options = ExtractionOptions::with_receipts(ReceiptsMode::SvgClip);
|
||
let result = extract_pdf(&pdf_path, &options).unwrap();
|
||
|
||
assert_eq!(result.metadata.receipts_mode, ReceiptsMode::SvgClip);
|
||
|
||
let page = &result.pages[0];
|
||
assert!(!page.spans.is_empty());
|
||
|
||
// Receipts should be present
|
||
// Note: In this minimal implementation without glyph data,
|
||
// SVG mode falls back to lite mode (svg_clip is None)
|
||
for span in &page.spans {
|
||
assert!(span.receipt.is_some());
|
||
let receipt = span.receipt.as_ref().unwrap();
|
||
assert_eq!(receipt.pdf_fingerprint, result.fingerprint);
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_result_to_json_format() {
|
||
let pdf_path = ensure_test_pdf();
|
||
|
||
let options = ExtractionOptions::default();
|
||
let result = extract_pdf(&pdf_path, &options).unwrap();
|
||
let json = result_to_json(&result);
|
||
|
||
assert!(json.is_object());
|
||
assert!(json.get("fingerprint").is_some());
|
||
assert!(json.get("schema_version").is_some());
|
||
assert!(json.get("pages").is_some());
|
||
assert!(json.get("metadata").is_some());
|
||
|
||
let pages = json.get("pages").and_then(|v| v.as_array()).unwrap();
|
||
assert_eq!(pages.len(), 1);
|
||
|
||
let page = &pages[0];
|
||
assert!(page.get("index").is_some());
|
||
assert!(page.get("spans").is_some());
|
||
assert!(page.get("blocks").is_some());
|
||
}
|
||
|
||
#[test]
|
||
fn test_result_to_json_with_receipts() {
|
||
let pdf_path = ensure_test_pdf();
|
||
|
||
let options = ExtractionOptions::with_receipts(ReceiptsMode::Lite);
|
||
let result = extract_pdf(&pdf_path, &options).unwrap();
|
||
let json = result_to_json(&result);
|
||
|
||
let pages = json.get("pages").and_then(|v| v.as_array()).unwrap();
|
||
let page = &pages[0];
|
||
let spans = page.get("spans").and_then(|v| v.as_array()).unwrap();
|
||
let span = &spans[0];
|
||
|
||
// Span should have receipt field
|
||
assert!(span.get("receipt").is_some());
|
||
|
||
let receipt = span.get("receipt").unwrap();
|
||
assert!(receipt.get("pdf_fingerprint").is_some());
|
||
assert!(receipt.get("page_index").is_some());
|
||
assert!(receipt.get("bbox").is_some());
|
||
assert!(receipt.get("content_hash").is_some());
|
||
assert!(receipt.get("extraction_version").is_some());
|
||
|
||
// svg_clip should not be present in lite mode
|
||
assert!(receipt.get("svg_clip").is_none());
|
||
}
|
||
|
||
#[test]
|
||
fn test_extraction_metadata() {
|
||
let pdf_path = ensure_test_pdf();
|
||
|
||
let options = ExtractionOptions::with_receipts(ReceiptsMode::Lite);
|
||
let result = extract_pdf(&pdf_path, &options).unwrap();
|
||
|
||
assert!(result.metadata.page_count >= 1);
|
||
assert!(result.metadata.span_count > 0);
|
||
assert!(result.metadata.block_count > 0);
|
||
assert_eq!(result.metadata.receipts_mode, ReceiptsMode::Lite);
|
||
}
|
||
}
|