eBookReaderSwitch/mupdf/source/pdf/pdf-cmap.c

933 lines
20 KiB
C
Raw Permalink Normal View History

#include "mupdf/fitz.h"
#include "mupdf/pdf.h"
#include <assert.h>
#include <string.h>
#undef CHECK_SPLAY
#undef DUMP_SPLAY
/*
* Allocate, destroy and simple parameters.
*/
void
pdf_drop_cmap_imp(fz_context *ctx, fz_storable *cmap_)
{
pdf_cmap *cmap = (pdf_cmap *)cmap_;
pdf_drop_cmap(ctx, cmap->usecmap);
fz_free(ctx, cmap->ranges);
fz_free(ctx, cmap->xranges);
fz_free(ctx, cmap->mranges);
fz_free(ctx, cmap->dict);
fz_free(ctx, cmap->tree);
fz_free(ctx, cmap);
}
pdf_cmap *
pdf_new_cmap(fz_context *ctx)
{
pdf_cmap *cmap = fz_malloc_struct(ctx, pdf_cmap);
FZ_INIT_STORABLE(cmap, 1, pdf_drop_cmap_imp);
return cmap;
}
/* Could be a macro for speed */
pdf_cmap *
pdf_keep_cmap(fz_context *ctx, pdf_cmap *cmap)
{
return fz_keep_storable(ctx, &cmap->storable);
}
/* Could be a macro for speed */
void
pdf_drop_cmap(fz_context *ctx, pdf_cmap *cmap)
{
fz_drop_storable(ctx, &cmap->storable);
}
void
pdf_set_usecmap(fz_context *ctx, pdf_cmap *cmap, pdf_cmap *usecmap)
{
int i;
pdf_drop_cmap(ctx, cmap->usecmap);
cmap->usecmap = pdf_keep_cmap(ctx, usecmap);
if (cmap->codespace_len == 0)
{
cmap->codespace_len = usecmap->codespace_len;
for (i = 0; i < usecmap->codespace_len; i++)
cmap->codespace[i] = usecmap->codespace[i];
}
}
int
pdf_cmap_wmode(fz_context *ctx, pdf_cmap *cmap)
{
return cmap->wmode;
}
void
pdf_set_cmap_wmode(fz_context *ctx, pdf_cmap *cmap, int wmode)
{
cmap->wmode = wmode;
}
/*
* Add a codespacerange section.
* These ranges are used by pdf_decode_cmap to decode
* multi-byte encoded strings.
*/
void
pdf_add_codespace(fz_context *ctx, pdf_cmap *cmap, unsigned int low, unsigned int high, int n)
{
if (cmap->codespace_len + 1 == nelem(cmap->codespace))
{
fz_warn(ctx, "assert: too many code space ranges");
return;
}
cmap->codespace[cmap->codespace_len].n = n;
cmap->codespace[cmap->codespace_len].low = low;
cmap->codespace[cmap->codespace_len].high = high;
cmap->codespace_len ++;
}
struct cmap_splay_s {
unsigned int low;
unsigned int high;
unsigned int out;
unsigned int left;
unsigned int right;
unsigned int parent : 31;
unsigned int many : 1;
};
#define EMPTY ((unsigned int)0x40000000)
/*
The splaying steps used:
Case 1: | z x
| y D => A y
| x C B z
| A B C D
Case 2: | z x
| y D => y z
| A x A B C D
| B C
Case 3: | y x
| x C => A y
| A B B C
*/
static void
move_to_root(cmap_splay *tree, unsigned int x)
{
if (x == EMPTY)
return;
do
{
unsigned int z, zp;
unsigned int y = tree[x].parent;
if (y == EMPTY)
break;
z = tree[y].parent;
if (z == EMPTY)
{
/* Case 3 */
tree[x].parent = EMPTY;
tree[y].parent = x;
if (tree[y].left == x)
{
/* Case 3 */
tree[y].left = tree[x].right;
if (tree[y].left != EMPTY)
tree[tree[y].left].parent = y;
tree[x].right = y;
}
else
{
/* Case 3 - reflected */
assert(tree[y].right == x);
tree[y].right = tree[x].left;
if (tree[y].right != EMPTY)
tree[tree[y].right].parent = y;
tree[x].left = y;
}
break;
}
zp = tree[z].parent;
tree[x].parent = zp;
if (zp != EMPTY) {
if (tree[zp].left == z)
tree[zp].left = x;
else
{
assert(tree[zp].right == z);
tree[zp].right = x;
}
}
tree[y].parent = x;
if (tree[y].left == x)
{
tree[y].left = tree[x].right;
if (tree[y].left != EMPTY)
tree[tree[y].left].parent = y;
tree[x].right = y;
if (tree[z].left == y)
{
/* Case 1 */
tree[z].parent = y;
tree[z].left = tree[y].right;
if (tree[z].left != EMPTY)
tree[tree[z].left].parent = z;
tree[y].right = z;
}
else
{
/* Case 2 - reflected */
assert(tree[z].right == y);
tree[z].parent = x;
tree[z].right = tree[x].left;
if (tree[z].right != EMPTY)
tree[tree[z].right].parent = z;
tree[x].left = z;
}
}
else
{
assert(tree[y].right == x);
tree[y].right = tree[x].left;
if (tree[y].right != EMPTY)
tree[tree[y].right].parent = y;
tree[x].left = y;
if (tree[z].left == y)
{
/* Case 2 */
tree[z].parent = x;
tree[z].left = tree[x].right;
if (tree[z].left != EMPTY)
tree[tree[z].left].parent = z;
tree[x].right = z;
}
else
{
/* Case 1 - reflected */
assert(tree[z].right == y);
tree[z].parent = y;
tree[z].right = tree[y].left;
if (tree[z].right != EMPTY)
tree[tree[z].right].parent = z;
tree[y].left = z;
}
}
} while (1);
}
static unsigned int delete_node(pdf_cmap *cmap, unsigned int current)
{
cmap_splay *tree = cmap->tree;
unsigned int parent;
unsigned int replacement;
assert(current != EMPTY);
parent = tree[current].parent;
if (tree[current].right == EMPTY)
{
if (parent == EMPTY)
{
replacement = cmap->ttop = tree[current].left;
}
else if (tree[parent].left == current)
{
replacement = tree[parent].left = tree[current].left;
}
else
{
assert(tree[parent].right == current);
replacement = tree[parent].right = tree[current].left;
}
if (replacement != EMPTY)
tree[replacement].parent = parent;
else
replacement = parent;
}
else if (tree[current].left == EMPTY)
{
if (parent == EMPTY)
{
replacement = cmap->ttop = tree[current].right;
}
else if (tree[parent].left == current)
{
replacement = tree[parent].left = tree[current].right;
}
else
{
assert(tree[parent].right == current);
replacement = tree[parent].right = tree[current].right;
}
if (replacement != EMPTY)
tree[replacement].parent = parent;
else
replacement = parent;
}
else
{
/* Hard case, find the in-order predecessor of current */
unsigned int amputee = current;
replacement = tree[current].left;
while (tree[replacement].right != EMPTY) {
amputee = replacement;
replacement = tree[replacement].right;
}
/* Remove replacement from the tree */
if (amputee == current)
{
tree[amputee].left = tree[replacement].left;
if (tree[amputee].left != EMPTY)
tree[tree[amputee].left].parent = amputee;
}
else
{
tree[amputee].right = tree[replacement].left;
if (tree[amputee].right != EMPTY)
tree[tree[amputee].right].parent = amputee;
}
/* Insert replacement in place of current */
tree[replacement].parent = parent;
if (parent == EMPTY)
{
tree[replacement].parent = EMPTY;
cmap->ttop = replacement;
}
else if (tree[parent].left == current)
tree[parent].left = replacement;
else
{
assert(tree[parent].right == current);
tree[parent].right = replacement;
}
tree[replacement].left = tree[current].left;
if (tree[replacement].left != EMPTY)
tree[tree[replacement].left].parent = replacement;
tree[replacement].right = tree[current].right;
if (tree[replacement].right != EMPTY)
tree[tree[replacement].right].parent = replacement;
}
/* current is now unlinked. We need to remove it from our array. */
cmap->tlen--;
if (current != (unsigned int) cmap->tlen)
{
if (replacement == (unsigned int) cmap->tlen)
replacement = current;
tree[current] = tree[cmap->tlen];
parent = tree[current].parent;
if (parent == EMPTY)
cmap->ttop = current;
else if (tree[parent].left == (unsigned int) cmap->tlen)
tree[parent].left = current;
else
{
assert(tree[parent].right == (unsigned int) cmap->tlen);
tree[parent].right = current;
}
if (tree[current].left != EMPTY)
{
assert(tree[tree[current].left].parent == (unsigned int) cmap->tlen);
tree[tree[current].left].parent = current;
}
if (tree[current].right != EMPTY)
{
assert(tree[tree[current].right].parent == (unsigned int) cmap->tlen);
tree[tree[current].right].parent = current;
}
}
/* Return the node that we should continue searching from */
return replacement;
}
#ifdef DUMP_SPLAY
static void
dump_splay(cmap_splay *tree, unsigned int node, int depth, const char *pre)
{
int i;
if (tree == NULL || node == EMPTY)
return;
for (i = 0; i < depth; i++)
fprintf(stderr, " ");
fprintf(stderr, "%s%d:", pre, node);
if (tree[node].parent == EMPTY)
fprintf(stderr, "^EMPTY");
else
fprintf(stderr, "^%d", tree[node].parent);
if (tree[node].left == EMPTY)
fprintf(stderr, "<EMPTY");
else
fprintf(stderr, "<%d", tree[node].left);
if (tree[node].right == EMPTY)
fprintf(stderr, ">EMPTY");
else
fprintf(stderr, ">%d", tree[node].right);
fprintf(stderr, "(%x,%x,%x,%d)\n", tree[node].low, tree[node].high, tree[node].out, tree[node].many);
assert(tree[node].parent == EMPTY || depth);
assert(tree[node].left == EMPTY || tree[tree[node].left].parent == node);
assert(tree[node].right == EMPTY || tree[tree[node].right].parent == node);
dump_splay(tree, tree[node].left, depth+1, "L");
dump_splay(tree, tree[node].right, depth+1, "R");
}
#endif
enum
{
TOP = 0,
LEFT = 1,
RIGHT = 2
};
static void walk_splay(cmap_splay *tree, unsigned int node, void (*fn)(cmap_splay *, void *), void *arg)
{
int from = TOP;
while (node != EMPTY)
{
switch (from)
{
case TOP:
if (tree[node].left != EMPTY)
{
node = tree[node].left;
from = TOP;
break;
}
/* fallthrough */
case LEFT:
fn(&tree[node], arg);
if (tree[node].right != EMPTY)
{
node = tree[node].right;
from = TOP;
break;
}
/* fallthrough */
case RIGHT:
{
unsigned int parent = tree[node].parent;
if (parent == EMPTY)
return;
if (tree[parent].left == node)
from = LEFT;
else
{
assert(tree[parent].right == node);
from = RIGHT;
}
node = parent;
}
}
}
}
#ifdef CHECK_SPLAY
static int
tree_has_overlap(cmap_splay *tree, int node, int low, int high)
{
if (tree[node].left != EMPTY)
if (tree_has_overlap(tree, tree[node].left, low, high))
return 1;
if (tree[node].right != EMPTY)
if (tree_has_overlap(tree, tree[node].right, low, high))
return 1;
return (tree[node].low < low && low < tree[node].high) || (tree[node].low < high && high < tree[node].high);
}
static void
do_check(cmap_splay *node, void *arg)
{
cmap_splay *tree = arg;
unsigned int num = node - tree;
assert(!node->many || node->low == node->high);
assert(node->low <= node->high);
assert((node->left == EMPTY) || (tree[node->left].parent == num &&
tree[node->left].high < node->low));
assert(node->right == EMPTY || (tree[node->right].parent == num &&
node->high < tree[node->right].low));
assert(!tree_has_overlap(tree, num, node->low, node->high));
}
static void
check_splay(cmap_splay *tree, unsigned int node, int depth)
{
if (node == EMPTY)
return;
assert(tree[node].parent == EMPTY);
walk_splay(tree, node, do_check, tree);
}
#endif
/*
* Add a range.
*/
static void
add_range(fz_context *ctx, pdf_cmap *cmap, unsigned int low, unsigned int high, unsigned int out, int check_for_overlap, int many)
{
int current;
cmap_splay *tree;
int i;
int inrange = 0;
unsigned int k, count;
if (low > high)
{
fz_warn(ctx, "range limits out of range in cmap %s", cmap->cmap_name);
return;
}
count = high - low + 1;
for (k = 0; k < count; k++) {
unsigned int c = low + k;
inrange = 0;
for (i = 0; i < cmap->codespace_len; i++) {
if (cmap->codespace[i].low <= c && c <= cmap->codespace[i].high)
inrange = 1;
}
if (!inrange)
{
fz_warn(ctx, "ignoring CMap range (%u-%u) that is outside of the codespace", low, high);
return;
}
}
tree = cmap->tree;
if (cmap->tlen)
{
unsigned int move = cmap->ttop;
unsigned int gt = EMPTY;
unsigned int lt = EMPTY;
if (check_for_overlap)
{
/* Check for collision with the current node */
do
{
current = move;
/* Cases we might meet:
* tree[i]: <----->
* case 0: <->
* case 1: <------->
* case 2: <------------->
* case 3: <->
* case 4: <------->
* case 5: <->
*/
if (low <= tree[current].low && tree[current].low <= high)
{
/* case 1, reduces to case 0 */
/* or case 2, deleting the node */
tree[current].out += high + 1 - tree[current].low;
tree[current].low = high + 1;
if (tree[current].low > tree[current].high)
{
/* update lt/gt references that will be moved/stale after deleting current */
if (gt == (unsigned int) cmap->tlen - 1)
gt = current;
if (lt == (unsigned int) cmap->tlen - 1)
lt = current;
/* delete_node() moves the element at cmap->tlen-1 into current */
move = delete_node(cmap, current);
current = EMPTY;
continue;
}
}
else if (low <= tree[current].high && tree[current].high <= high)
{
/* case 4, reduces to case 5 */
tree[current].high = low - 1;
assert(tree[current].low <= tree[current].high);
}
else if (tree[current].low < low && high < tree[current].high)
{
/* case 3, reduces to case 5 */
int new_high = tree[current].high;
tree[current].high = low-1;
add_range(ctx, cmap, high+1, new_high, tree[current].out + high + 1 - tree[current].low, 0, tree[current].many);
tree = cmap->tree;
}
/* Now look for where to move to next (left for case 0, right for case 5) */
if (tree[current].low > high) {
move = tree[current].left;
gt = current;
}
else
{
move = tree[current].right;
lt = current;
}
}
while (move != EMPTY);
}
else
{
do
{
current = move;
if (tree[current].low > high)
{
move = tree[current].left;
gt = current;
}
else
{
move = tree[current].right;
lt = current;
}
} while (move != EMPTY);
}
/* current is now the node to which we would be adding the new node */
/* lt is the last node we traversed which is lt the new node. */
/* gt is the last node we traversed which is gt the new node. */
if (!many)
{
/* Check for the 'merge' cases. */
if (lt != EMPTY && !tree[lt].many && tree[lt].high == low-1 && tree[lt].out - tree[lt].low == out - low)
{
tree[lt].high = high;
if (gt != EMPTY && !tree[gt].many && tree[gt].low == high+1 && tree[gt].out - tree[gt].low == out - low)
{
tree[lt].high = tree[gt].high;
delete_node(cmap, gt);
}
goto exit;
}
if (gt != EMPTY && !tree[gt].many && tree[gt].low == high+1 && tree[gt].out - tree[gt].low == out - low)
{
tree[gt].low = low;
tree[gt].out = out;
goto exit;
}
}
}
else
current = EMPTY;
if (cmap->tlen == cmap->tcap)
{
int new_cap = cmap->tcap ? cmap->tcap * 2 : 256;
tree = cmap->tree = fz_realloc_array(ctx, cmap->tree, new_cap, cmap_splay);
cmap->tcap = new_cap;
}
tree[cmap->tlen].low = low;
tree[cmap->tlen].high = high;
tree[cmap->tlen].out = out;
tree[cmap->tlen].parent = current;
tree[cmap->tlen].left = EMPTY;
tree[cmap->tlen].right = EMPTY;
tree[cmap->tlen].many = many;
cmap->tlen++;
if (current == EMPTY)
cmap->ttop = 0;
else if (tree[current].low > high)
tree[current].left = cmap->tlen-1;
else
{
assert(tree[current].high < low);
tree[current].right = cmap->tlen-1;
}
move_to_root(tree, cmap->tlen-1);
cmap->ttop = cmap->tlen-1;
exit:
{}
#ifdef CHECK_SPLAY
check_splay(cmap->tree, cmap->ttop, 0);
#endif
#ifdef DUMP_SPLAY
dump_splay(cmap->tree, cmap->ttop, 0, "");
#endif
}
/*
* Add a one-to-many mapping.
*/
static void
add_mrange(fz_context *ctx, pdf_cmap *cmap, unsigned int low, int *out, int len)
{
int out_pos;
if (cmap->dlen + len + 1 > cmap->dcap)
{
int new_cap = cmap->dcap ? cmap->dcap * 2 : 256;
cmap->dict = fz_realloc_array(ctx, cmap->dict, new_cap, int);
cmap->dcap = new_cap;
}
out_pos = cmap->dlen;
cmap->dict[out_pos] = len;
memcpy(&cmap->dict[out_pos+1], out, sizeof(int)*len);
cmap->dlen += len + 1;
add_range(ctx, cmap, low, low, out_pos, 1, 1);
}
/*
* Add a range of contiguous one-to-one mappings (ie 1..5 maps to 21..25)
*/
void
pdf_map_range_to_range(fz_context *ctx, pdf_cmap *cmap, unsigned int low, unsigned int high, int out)
{
add_range(ctx, cmap, low, high, out, 1, 0);
}
/*
* Add a single one-to-many mapping.
*/
void
pdf_map_one_to_many(fz_context *ctx, pdf_cmap *cmap, unsigned int low, int *values, int len)
{
if (len == 1)
{
add_range(ctx, cmap, low, low, values[0], 1, 0);
return;
}
/* Decode unicode surrogate pairs. */
/* Only the *-UCS2 CMaps use one-to-many mappings, so assuming unicode should be safe. */
if (len == 2 &&
values[0] >= 0xD800 && values[0] <= 0xDBFF &&
values[1] >= 0xDC00 && values[1] <= 0xDFFF)
{
int rune = ((values[0] - 0xD800) << 10) + (values[1] - 0xDC00) + 0x10000;
add_range(ctx, cmap, low, low, rune, 1, 0);
return;
}
if (len > PDF_MRANGE_CAP)
{
fz_warn(ctx, "ignoring one to many mapping in cmap %s", cmap->cmap_name);
return;
}
add_mrange(ctx, cmap, low, values, len);
}
static void
count_node_types(cmap_splay *node, void *arg)
{
int *counts = (int *)arg;
if (node->many)
counts[2]++;
else if (node->low <= 0xffff && node->high <= 0xFFFF && node->out <= 0xFFFF)
counts[0]++;
else
counts[1]++;
}
static void
copy_node_types(cmap_splay *node, void *arg)
{
pdf_cmap *cmap = (pdf_cmap *)arg;
if (node->many)
{
assert(node->low == node->high);
cmap->mranges[cmap->mlen].low = node->low;
cmap->mranges[cmap->mlen].out = node->out;
cmap->mlen++;
}
else if (node->low <= 0xffff && node->high <= 0xFFFF && node->out <= 0xFFFF)
{
cmap->ranges[cmap->rlen].low = node->low;
cmap->ranges[cmap->rlen].high = node->high;
cmap->ranges[cmap->rlen].out = node->out;
cmap->rlen++;
}
else
{
cmap->xranges[cmap->xlen].low = node->low;
cmap->xranges[cmap->xlen].high = node->high;
cmap->xranges[cmap->xlen].out = node->out;
cmap->xlen++;
}
}
void
pdf_sort_cmap(fz_context *ctx, pdf_cmap *cmap)
{
int counts[3];
if (cmap->tree == NULL)
return;
counts[0] = 0;
counts[1] = 0;
counts[2] = 0;
walk_splay(cmap->tree, cmap->ttop, count_node_types, &counts);
cmap->ranges = fz_malloc_array(ctx, counts[0], pdf_range);
cmap->rcap = counts[0];
cmap->xranges = fz_malloc_array(ctx, counts[1], pdf_xrange);
cmap->xcap = counts[1];
cmap->mranges = fz_malloc_array(ctx, counts[2], pdf_mrange);
cmap->mcap = counts[2];
walk_splay(cmap->tree, cmap->ttop, copy_node_types, cmap);
fz_free(ctx, cmap->tree);
cmap->tree = NULL;
}
/*
* Lookup the mapping of a codepoint.
*/
int
pdf_lookup_cmap(pdf_cmap *cmap, unsigned int cpt)
{
pdf_range *ranges = cmap->ranges;
pdf_xrange *xranges = cmap->xranges;
int l, r, m;
l = 0;
r = cmap->rlen - 1;
while (l <= r)
{
m = (l + r) >> 1;
if (cpt < ranges[m].low)
r = m - 1;
else if (cpt > ranges[m].high)
l = m + 1;
else
return cpt - ranges[m].low + ranges[m].out;
}
l = 0;
r = cmap->xlen - 1;
while (l <= r)
{
m = (l + r) >> 1;
if (cpt < xranges[m].low)
r = m - 1;
else if (cpt > xranges[m].high)
l = m + 1;
else
return cpt - xranges[m].low + xranges[m].out;
}
if (cmap->usecmap)
return pdf_lookup_cmap(cmap->usecmap, cpt);
return -1;
}
int
pdf_lookup_cmap_full(pdf_cmap *cmap, unsigned int cpt, int *out)
{
pdf_range *ranges = cmap->ranges;
pdf_xrange *xranges = cmap->xranges;
pdf_mrange *mranges = cmap->mranges;
unsigned int i;
int l, r, m;
l = 0;
r = cmap->rlen - 1;
while (l <= r)
{
m = (l + r) >> 1;
if (cpt < ranges[m].low)
r = m - 1;
else if (cpt > ranges[m].high)
l = m + 1;
else
{
out[0] = cpt - ranges[m].low + ranges[m].out;
return 1;
}
}
l = 0;
r = cmap->xlen - 1;
while (l <= r)
{
m = (l + r) >> 1;
if (cpt < xranges[m].low)
r = m - 1;
else if (cpt > xranges[m].high)
l = m + 1;
else
{
out[0] = cpt - xranges[m].low + xranges[m].out;
return 1;
}
}
l = 0;
r = cmap->mlen - 1;
while (l <= r)
{
m = (l + r) >> 1;
if (cpt < mranges[m].low)
r = m - 1;
else if (cpt > mranges[m].low)
l = m + 1;
else
{
int *ptr = &cmap->dict[cmap->mranges[m].out];
unsigned int len = (unsigned int)*ptr++;
for (i = 0; i < len; ++i)
out[i] = *ptr++;
return len;
}
}
if (cmap->usecmap)
return pdf_lookup_cmap_full(cmap->usecmap, cpt, out);
return 0;
}
/*
* Use the codespace ranges to extract a codepoint from a
* multi-byte encoded string.
*/
int
pdf_decode_cmap(pdf_cmap *cmap, unsigned char *buf, unsigned char *end, unsigned int *cpt)
{
unsigned int c;
int k, n;
int len = end - buf;
if (len > 4)
len = 4;
c = 0;
for (n = 0; n < len; n++)
{
c = (c << 8) | buf[n];
for (k = 0; k < cmap->codespace_len; k++)
{
if (cmap->codespace[k].n == n + 1)
{
if (c >= cmap->codespace[k].low && c <= cmap->codespace[k].high)
{
*cpt = c;
return n + 1;
}
}
}
}
*cpt = 0;
return 1;
}