forked from pdfcpu/pdfcpu
/
write_buf.go
100 lines (76 loc) · 2.05 KB
/
write_buf.go
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package pdfcpu
import (
"bufio"
"bytes"
"github.com/mysilkway/pdfcpu/pkg/log"
)
// WritePDFBuf generates a PDF file buffer for the cross reference table contained in Context.
func WritePDFBuf(ctx *Context) (*bytes.Buffer, error) {
b := bytes.NewBuffer([]byte{})
ctx.Write.Writer = bufio.NewWriter(b)
err := handleEncryption(ctx)
if err != nil {
return nil, err
}
// Since we support PDF Collections (since V1.7) for file attachments
// we need to always generate V1.7 PDF files.
err = writeHeader(ctx.Write, V17)
if err != nil {
return nil, err
}
log.Debug.Printf("offset after writeHeader: %d\n", ctx.Write.Offset)
// Write root object(aka the document catalog) and page tree.
err = writeRootObject(ctx)
if err != nil {
return nil, err
}
log.Debug.Printf("offset after writeRootObject: %d\n", ctx.Write.Offset)
// Write document information dictionary.
err = writeDocumentInfoDict(ctx)
if err != nil {
return nil, err
}
log.Debug.Printf("offset after writeInfoObject: %d\n", ctx.Write.Offset)
// Write offspec additional streams as declared in pdf trailer.
if ctx.AdditionalStreams != nil {
_, _, err = writeDeepObject(ctx, ctx.AdditionalStreams)
if err != nil {
return nil, err
}
}
err = writeEncryptDict(ctx)
if err != nil {
return nil, err
}
// Mark redundant objects as free.
// eg. duplicate resources, compressed objects, linearization dicts..
deleteRedundantObjects(ctx)
err = writeXRef(ctx)
if err != nil {
return nil, err
}
// Write pdf trailer.
_, err = writeTrailer(ctx.Write)
if err != nil {
return nil, err
}
err = setFileSizeOfWrittenFileBuf(ctx.Write)
if err != nil {
return nil, err
}
if ctx.Read != nil {
ctx.Write.BinaryImageSize = ctx.Read.BinaryImageSize
ctx.Write.BinaryFontSize = ctx.Read.BinaryFontSize
logWriteStats(ctx)
}
return b, nil
}
func setFileSizeOfWrittenFileBuf(w *WriteContext) error {
// Get file info for file just written but flush first to get correct file size.
err := w.Flush()
if err != nil {
return err
}
w.FileSize = int64(w.Size())
return nil
}