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/*
* This file is part of libdom.
* Licensed under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
* Copyright 2007 John-Mark Bell <jmb@netsurf-browser.org>
*/
#include <inttypes.h>
#include <string.h>
#include <dom/ctx.h>
#include <dom/core/string.h>
#include "core/document.h"
#include "utils/utils.h"
/**
* A DOM string
*
* DOM strings store either a pointer to allocated data, a pointer
* to constant data or an offset into a document buffer.
*
* They are reference counted so freeing is performed correctly.
*/
struct dom_string {
enum { DOM_STRING_PTR,
DOM_STRING_CONST_PTR,
DOM_STRING_OFFSET
} type;
union {
uint8_t *ptr;
const uint8_t *cptr;
struct {
struct dom_document *doc;
uint32_t off;
} offset;
} data;
size_t len;
uint32_t refcnt;
};
/**
* Claim a reference on a DOM string
*
* \param ctx The context in which the string resides
* \param str The string to claim a reference on
*/
void dom_string_ref(struct dom_ctx *ctx, struct dom_string *str)
{
UNUSED(ctx);
str->refcnt++;
}
/**
* Release a reference on a DOM string
*
* \param ctx The context in which the string resides
* \param str The string to release the reference from
*
* If the reference count reaches zero, any memory claimed by the
* string will be released
*/
void dom_string_unref(struct dom_ctx *ctx, struct dom_string *str)
{
if (--str->refcnt == 0) {
if (str->type == DOM_STRING_PTR)
ctx->alloc(str->data.ptr, 0, ctx->pw);
ctx->alloc(str, 0, ctx->pw);
}
}
/**
* Create a DOM string from an offset into the document buffer
*
* \param ctx The context in which the string resides
* \param doc The document in which the string resides
* \param off Offset from start of document buffer
* \param len Length, in bytes, of string
* \param str Pointer to location to receive pointer to new string
* \return DOM_NO_ERR on success, DOM_NO_MEM_ERR on memory exhaustion
*
* The returned string will already be referenced, so there is no need
* to explicitly reference it.
*/
dom_exception dom_string_create_from_off(struct dom_ctx *ctx,
struct dom_document *doc, uint32_t off, size_t len,
struct dom_string **str)
{
struct dom_string *ret;
ret = ctx->alloc(NULL, sizeof(struct dom_string), ctx->pw);
if (ret == NULL)
return DOM_NO_MEM_ERR;
ret->type = DOM_STRING_OFFSET;
ret->data.offset.doc = doc;
ret->data.offset.off = off;
ret->len = len;
ret->refcnt = 1;
*str = ret;
return DOM_NO_ERR;
}
/**
* Create a DOM string from a string of characters
*
* \param ctx The context in which the string resides
* \param ptr Pointer to string of characters
* \param len Length, in bytes, of string of characters
* \param str Pointer to location to receive pointer to new string
* \return DOM_NO_ERR on success, DOM_NO_MEM_ERR on memory exhaustion
*
* The returned string will already be referenced, so there is no need
* to explicitly reference it.
*
* The string of characters passed in will be copied for use by the
* returned DOM string.
*/
dom_exception dom_string_create_from_ptr(struct dom_ctx *ctx,
const uint8_t *ptr, size_t len, struct dom_string **str)
{
struct dom_string *ret;
ret = ctx->alloc(NULL, sizeof(struct dom_string), ctx->pw);
if (ret == NULL)
return DOM_NO_MEM_ERR;
ret->data.ptr = ctx->alloc(NULL, len, ctx->pw);
if (ret->data.ptr == NULL) {
ctx->alloc(ret, 0, ctx->pw);
return DOM_NO_MEM_ERR;
}
ret->type = DOM_STRING_PTR;
memcpy(ret->data.ptr, ptr, len);
ret->len = len;
ret->refcnt = 1;
*str = ret;
return DOM_NO_ERR;
}
/**
* Create a DOM string from a constant string of characters
*
* \param ctx The context in which the string resides
* \param ptr Pointer to string of characters
* \param len Length, in bytes, of string of characters
* \param str Pointer to location to receive pointer to new string
* \return DOM_NO_ERR on success, DOM_NO_MEM_ERR on memory exhaustion
*
* The returned string will already be referenced, so there is no need
* to explicitly reference it.
*
* The string of characters passed in will _not_ be copied for use by the
* returned DOM string.
*/
dom_exception dom_string_create_from_const_ptr(struct dom_ctx *ctx,
const uint8_t *ptr, size_t len, struct dom_string **str)
{
struct dom_string *ret;
ret = ctx->alloc(NULL, sizeof(struct dom_string), ctx->pw);
if (ret == NULL)
return DOM_NO_MEM_ERR;
ret->data.cptr = ptr;
ret->type = DOM_STRING_CONST_PTR;
ret->len = len;
ret->refcnt = 1;
*str = ret;
return DOM_NO_ERR;
}
/**
* Get a pointer to the string of characters within a DOM string
*
* \param ctx The context in which the string resides
* \param str Pointer to DOM string to retrieve pointer from
* \param data Pointer to location to receive data
* \param len Pointer to location to receive byte length of data
* \return DOM_NO_ERR on success
*
* The caller must have previously claimed a reference on the DOM string.
* The returned pointer must not be freed.
*/
dom_exception dom_string_get_data(struct dom_ctx *ctx,
struct dom_string *str, const uint8_t **data, size_t *len)
{
switch (str->type) {
case DOM_STRING_PTR:
*data = str->data.ptr;
break;
case DOM_STRING_CONST_PTR:
*data = str->data.cptr;
break;
case DOM_STRING_OFFSET:
*data = dom_document_get_base(ctx, str->data.offset.doc) +
str->data.offset.off;
break;
}
*len = str->len;
return DOM_NO_ERR;
}
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