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add loading by page
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@linusbierhoff @jrmuizel
linusbierhoff authored and jrmuizel committed Oct 6, 2024
1 parent f456267 commit b763470
Showing 1 changed file with 101 additions and 20 deletions.
121 changes: 101 additions & 20 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -768,7 +768,7 @@ impl<'a> PdfFont for PdfSimpleFont<'a> {
if let Some(ref unicode_map) = self.unicode_map {
let s = unicode_map.get(&char);
let s = match s {
None => {
None => {
println!("missing char {:?} in unicode map {:?} for {:?}", char, unicode_map, self.font);
// some pdf's like http://arxiv.org/pdf/2312.00064v1 are missing entries in their unicode map but do have
// entries in the encoding.
Expand Down Expand Up @@ -2188,6 +2188,75 @@ pub fn extract_text_from_mem_encrypted<PW: AsRef<[u8]>>(
Ok(s)
}


fn extract_text_by_page(doc: &Document, page_num: u32) -> Result<String, OutputError> {
let mut s = String::new();
{
let mut output = PlainTextOutput::new(&mut s);
output_doc_page(doc, &mut output, page_num)?;
}
Ok(s)
}

/// Extract the text from a pdf at `path` and return a `Vec<String>` with the results separately by page
pub fn extract_text_by_pages<P: std::convert::AsRef<std::path::Path>>(path: P) -> Result<Vec<String>, OutputError> {
let mut v = Vec::new();
{
let mut doc = Document::load(path)?;
maybe_decrypt(&mut doc)?;
let mut page_num = 1;
while let Ok(content) = extract_text_by_page(&doc, page_num) {
v.push(content);
page_num += 1;
}
}
Ok(v)
}

pub fn extract_text_by_pages_encrypted<P: std::convert::AsRef<std::path::Path>, PW: AsRef<[u8]>>(path: P, password: PW) -> Result<Vec<String>, OutputError> {
let mut v = Vec::new();
{
let mut doc = Document::load(path)?;
doc.decrypt(password)?;
let mut page_num = 1;
while let Ok(content) = extract_text_by_page(&mut doc, page_num) {
v.push(content);
page_num += 1;
}
}
Ok(v)
}

pub fn extract_text_from_mem_by_pages(buffer: &[u8]) -> Result<Vec<String>, OutputError> {
let mut v = Vec::new();
{
let mut doc = Document::load_mem(buffer)?;
maybe_decrypt(&mut doc)?;
let mut page_num = 1;
while let Ok(content) = extract_text_by_page(&doc, page_num) {
v.push(content);
page_num += 1;
}
}
Ok(v)
}

pub fn extract_text_from_mem_by_pages_encrypted<PW: AsRef<[u8]>>(buffer: &[u8], password: PW) -> Result<Vec<String>, OutputError> {
let mut v = Vec::new();
{
let mut doc = Document::load_mem(buffer)?;
doc.decrypt(password)?;
let mut page_num = 1;
while let Ok(content) = extract_text_by_page(&doc, page_num) {
v.push(content);
page_num += 1;
}
}
Ok(v)
}


fn get_inherited<'a, T: FromObj<'a>>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> Option<T> {
let o: Option<T> = get(doc, dict, key);
if let Some(o) = o {
Expand All @@ -2214,30 +2283,42 @@ pub fn output_doc(doc: &Document, output: &mut dyn OutputDev) -> Result<(), Outp
if doc.is_encrypted() {
eprintln!("Encrypted documents must be decrypted with a password using {{extract_text|extract_text_from_mem|output_doc}}_encrypted");
}
let empty_resources = &Dictionary::new();

let empty_resources = Dictionary::new();
let pages = doc.get_pages();
let mut p = Processor::new();
for dict in pages {
let page_num = dict.0;
let page_dict = doc.get_object(dict.1).unwrap().as_dict().unwrap();
dlog!("page {} {:?}", page_num, page_dict);
// XXX: Some pdfs lack a Resources directory
let resources = get_inherited(doc, page_dict, b"Resources").unwrap_or(empty_resources);
dlog!("resources {:?}", resources);

// pdfium searches up the page tree for MediaBoxes as needed
let media_box: Vec<f64> = get_inherited(doc, page_dict, b"MediaBox").expect("MediaBox");
let media_box = MediaBox { llx: media_box[0], lly: media_box[1], urx: media_box[2], ury: media_box[3] };

let art_box = get::<Option<Vec<f64>>>(&doc, page_dict, b"ArtBox")
.map(|x| (x[0], x[1], x[2], x[3]));

output.begin_page(page_num, &media_box, art_box)?;

p.process_stream(&doc, doc.get_page_content(dict.1).unwrap(), resources,&media_box, output, page_num)?;
let object_id = dict.1;
output_doc_inner(page_num, object_id, doc, &mut p, output, &empty_resources)?;
}
Ok(())
}

output.end_page()?;
pub fn output_doc_page(doc: &Document, output: &mut dyn OutputDev, page_num: u32) -> Result<(), OutputError> {
if doc.is_encrypted() {
eprintln!("Encrypted documents must be decrypted with a password using {{extract_text|extract_text_from_mem|output_doc}}_encrypted");
}
let empty_resources = Dictionary::new();
let pages = doc.get_pages();
let object_id = pages.get(&page_num).ok_or(lopdf::Error::PageNumberNotFound(page_num))?;
let mut p = Processor::new();
output_doc_inner(page_num, *object_id, doc, &mut p, output, &empty_resources)?;
Ok(())
}

fn output_doc_inner<'a>(page_num: u32, object_id: ObjectId, doc: &'a Document, p: & mut Processor<'a>, output: &mut dyn OutputDev, empty_resources: &'a Dictionary) -> Result<(), OutputError> {
let page_dict = doc.get_object(object_id).unwrap().as_dict().unwrap();
dlog!("page {} {:?}", page_num, page_dict);
// XXX: Some pdfs lack a Resources directory
let resources = get_inherited(doc, page_dict, b"Resources").unwrap_or(empty_resources);
dlog!("resources {:?}", resources);
// pdfium searches up the page tree for MediaBoxes as needed
let media_box: Vec<f64> = get_inherited(doc, page_dict, b"MediaBox").expect("MediaBox");
let media_box = MediaBox { llx: media_box[0], lly: media_box[1], urx: media_box[2], ury: media_box[3] };
let art_box = get::<Option<Vec<f64>>>(&doc, page_dict, b"ArtBox")
.map(|x| (x[0], x[1], x[2], x[3]));
output.begin_page(page_num, &media_box, art_box)?;
p.process_stream(&doc, doc.get_page_content(object_id).unwrap(), resources, &media_box, output, page_num)?;
output.end_page()?;
Ok(())
}

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