Zig Requires Chilkat v11.7.0+

PDF Object Streams: generate, preserve or disable

See more PDF Optimization Examples

Demonstrates the objectStreams option. An object stream packs many small objects (dictionaries, not stream data) into one compressed stream, which is usually a worthwhile saving in a document with many pages or tags. "generate" (the default) packs them and writes a cross-reference stream; "preserve" keeps the file as it is -- packed if it already was, not packed if it was not; "disable" writes every object on its own with a classic cross-reference table, which is what a PDF 1.4 reader needs. Object streams require PDF 1.5 and are skipped for PDF/A-1. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // The PDF used in this example is available at grand_canyon_hiking_guide.pdf

    const fac = try chilkat.FileAccess.init();
    defer fac.deinit();
    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    const json_out = try chilkat.JsonObject.init();
    defer json_out.deinit();

    // generate: pack the objects (the default).
    const pdf1 = try chilkat.Pdf.init();
    defer pdf1.deinit();
    pdf1.loadFile("qa_data/pdf/grand_canyon_hiking_guide.pdf") catch {
        std.debug.print("{s}\n", .{try pdf1.getLastErrorText(alloc)});
        return;
    };

    json.updateString("objectStreams", "generate") catch {};
    pdf1.optimize("optimize", json, json_out) catch {
        std.debug.print("{s}\n", .{try pdf1.getLastErrorText(alloc)});
        return;
    };

    pdf1.writeFile("qa_output/grand_canyon_objstm_generate.pdf") catch {
        std.debug.print("{s}\n", .{try pdf1.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("generate: {d} bytes, objects packed: {d}\n", .{ fac.fileSize("qa_output/grand_canyon_objstm_generate.pdf"), json_out.intOf("actions.objectStreams.count") });

    // disable: every object on its own, with a classic cross-reference table.
    const pdf2 = try chilkat.Pdf.init();
    defer pdf2.deinit();
    pdf2.loadFile("qa_data/pdf/grand_canyon_hiking_guide.pdf") catch {
        std.debug.print("{s}\n", .{try pdf2.getLastErrorText(alloc)});
        return;
    };

    json.updateString("objectStreams", "disable") catch {};
    pdf2.optimize("optimize", json, json_out) catch {
        std.debug.print("{s}\n", .{try pdf2.getLastErrorText(alloc)});
        return;
    };

    pdf2.writeFile("qa_output/grand_canyon_objstm_disable.pdf") catch {
        std.debug.print("{s}\n", .{try pdf2.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("disable:  {d} bytes\n", .{fac.fileSize("qa_output/grand_canyon_objstm_disable.pdf")});

    // preserve: leave the file's own structure alone.  Use it when the output must stay readable by
    // whatever reads the input today.
    const pdf3 = try chilkat.Pdf.init();
    defer pdf3.deinit();
    pdf3.loadFile("qa_data/pdf/grand_canyon_hiking_guide.pdf") catch {
        std.debug.print("{s}\n", .{try pdf3.getLastErrorText(alloc)});
        return;
    };

    json.updateString("objectStreams", "preserve") catch {};
    pdf3.optimize("optimize", json, json_out) catch {
        std.debug.print("{s}\n", .{try pdf3.getLastErrorText(alloc)});
        return;
    };

    pdf3.writeFile("qa_output/grand_canyon_objstm_preserve.pdf") catch {
        std.debug.print("{s}\n", .{try pdf3.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("preserve: {d} bytes\n", .{fac.fileSize("qa_output/grand_canyon_objstm_preserve.pdf")});
}