diff options
Diffstat (limited to 'mupdf/pdf_doctor.c')
| -rw-r--r-- | mupdf/pdf_doctor.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/mupdf/pdf_doctor.c b/mupdf/pdf_doctor.c new file mode 100644 index 00000000..be683592 --- /dev/null +++ b/mupdf/pdf_doctor.c @@ -0,0 +1,273 @@ +#include <fitz.h> +#include <mupdf.h> + +/* + * Sweep and mark reachable objects + */ + +static fz_error *sweepref(pdf_xref *xref, fz_obj *ref); + +static fz_error * +sweepobj(pdf_xref *xref, fz_obj *obj) +{ + fz_error *error; + int i; + + if (fz_isdict(obj)) + { + for (i = 0; i < fz_dictlen(obj); i++) + { + error = sweepobj(xref, fz_dictgetval(obj, i)); + if (error) + return error; + } + } + + if (fz_isarray(obj)) + { + for (i = 0; i < fz_arraylen(obj); i++) + { + error = sweepobj(xref, fz_arrayget(obj, i)); + if (error) + return error; + } + } + + if (fz_isindirect(obj)) + return sweepref(xref, obj); + + return nil; +} + +static fz_error * +sweepref(pdf_xref *xref, fz_obj *ref) +{ + fz_error *error; + fz_obj *obj; + int oid; + + oid = fz_tonum(ref); + + if (oid < 0 || oid >= xref->len) + return fz_throw("rangecheck: object number out of range"); + + if (xref->table[oid].mark) + return nil; + + xref->table[oid].mark = 1; + + error = pdf_loadindirect(&obj, xref, ref); + if (error) + return error; + + error = sweepobj(xref, obj); + if (error) + { + fz_dropobj(obj); + return error; + } + + fz_dropobj(obj); + return nil; +} + +/* + * Garbage collect objects not reachable from + * the trailer dictionary + */ + +fz_error * +pdf_garbagecollect(pdf_xref *xref) +{ + fz_error *error; + int i, g; + + pdf_logxref("garbage collect {\n"); + + for (i = 0; i < xref->len; i++) + xref->table[i].mark = 0; + + error = sweepobj(xref, xref->trailer); + if (error) + return error; + + for (i = 0; i < xref->len; i++) + { + pdf_xrefentry *x = xref->table + i; + g = x->gen; + if (x->type == 'o') + g = 0; + if (!x->mark && x->type != 'f' && x->type != 'd') + pdf_deleteobject(xref, i, g); + } + + pdf_logxref("}\n"); + + return nil; +} + +/* + * Transplant (copy) objects and streams from one file to another + */ + +struct pair +{ + int soid, sgen; + int doid, dgen; +}; + +static fz_error * +remaprefs(fz_obj **newp, fz_obj *old, struct pair *map, int n) +{ + fz_error *error; + int i, o, g; + fz_obj *tmp, *key; + + if (fz_isindirect(old)) + { + o = fz_tonum(old); + g = fz_togen(old); + for (i = 0; i < n; i++) + if (map[i].soid == o && map[i].sgen == g) + return fz_newindirect(newp, map[i].doid, map[i].dgen); + } + + else if (fz_isarray(old)) + { + error = fz_newarray(newp, fz_arraylen(old)); + if (error) + return error; + for (i = 0; i < fz_arraylen(old); i++) + { + tmp = fz_arrayget(old, i); + error = remaprefs(&tmp, tmp, map, n); + if (error) + goto cleanup; + error = fz_arraypush(*newp, tmp); + fz_dropobj(tmp); + if (error) + goto cleanup; + } + } + + else if (fz_isdict(old)) + { + error = fz_newdict(newp, fz_dictlen(old)); + if (error) + return error; + for (i = 0; i < fz_dictlen(old); i++) + { + key = fz_dictgetkey(old, i); + tmp = fz_dictgetval(old, i); + error = remaprefs(&tmp, tmp, map, n); + if (error) + goto cleanup; + error = fz_dictput(*newp, key, tmp); + fz_dropobj(tmp); + if (error) + goto cleanup; + } + } + + else + { + *newp = fz_keepobj(old); + } + + return nil; + +cleanup: + fz_dropobj(*newp); + return error; +} + +/* + * Recursively copy objects from src to dst xref. + * Start with root object in src xref. + * Put the dst copy of root into newp. + */ +fz_error * +pdf_transplant(pdf_xref *dst, pdf_xref *src, fz_obj **newp, fz_obj *root) +{ + fz_error *error; + struct pair *map; + fz_obj *old, *new; + fz_buffer *stm; + int i, n; + + pdf_logxref("transplant {\n"); + + for (i = 0; i < src->len; i++) + src->table[i].mark = 0; + + error = sweepobj(src, root); + if (error) + return error; + + for (n = 0, i = 0; i < src->len; i++) + if (src->table[i].mark) + n++; + + pdf_logxref("marked %d\n", n); + + map = fz_malloc(sizeof(struct pair) * n); + if (!map) + return fz_outofmem; + + for (n = 0, i = 0; i < src->len; i++) + { + if (src->table[i].mark) + { + map[n].soid = i; + map[n].sgen = src->table[i].gen; + if (src->table[i].type == 'o') + map[n].sgen = 0; + error = pdf_allocobject(dst, &map[n].doid, &map[n].dgen); + if (error) + goto cleanup; + n++; + } + } + + error == remaprefs(newp, root, map, n); + if (error) + goto cleanup; + + for (i = 0; i < n; i++) + { + pdf_logxref("copyfrom %d %d to %d %d\n", + map[i].soid, map[i].sgen, + map[i].doid, map[i].dgen); + + error = pdf_loadobject(&old, src, map[i].soid, map[i].sgen); + if (error) + goto cleanup; + + if (pdf_isstream(src, map[i].soid, map[i].sgen)) + { + error = pdf_loadrawstream(&stm, src, map[i].soid, map[i].sgen); + if (error) + goto cleanup; + pdf_updatestream(dst, map[i].doid, map[i].dgen, stm); + fz_dropbuffer(stm); + } + + error = remaprefs(&new, old, map, n); + fz_dropobj(old); + if (error) + goto cleanup; + + pdf_updateobject(dst, map[i].doid, map[i].dgen, new); + fz_dropobj(new); + } + + pdf_logxref("}\n"); + + fz_free(map); + return nil; + +cleanup: + fz_free(map); + return error; +} + |